How to Pipe a Cupcake
Before you pipe a cupcake, try practicing on a plate or parchment paper so that you know exactly how much pressure to apply. When you're ready, squeeze the icing bag over the center of the cupcake, then continue to squeeze as you pipe a tight circle around the center. When the circle is finished, spiral the piping tip inwards to come back to center. Finally, stop squeezing the bag in order to release the pressure, then gently lift the bag to create a point.
Make the frosting right before you're ready to pipe. Frosting will dry out and harden if exposed to air, so don't let it sit around while you wait for your cupcakes to finish. A thick buttercream frosting will be best for creating your decorations. Frosting or icing recipes which only use powdered sugar and liquid are more difficult to pipe due to their thinner consistency. If you need to store your frosting, or you have a lengthy decorating session planned, keep any frosting you're not using in an airtight container. If your frosting develops hardened lumps, add a few drops of milk or water at a time, stirring them in to see if the hardened lumps mix into the rest of the frosting. Buy a piping bag or make your own. Piping bags, also called pastry bags, are canvas or plastic cones with a hole at the tip to squeeze the frosting out of. If you don't own one, you can easily make your own following the instructions in this linked article. You can use a rectangular plastic bag (such as a ziploc bag) and cut a hole in one corner, or cut out a large, long triangle of parchment paper and wrap it in a circle to make a cone. If you use parchment paper, make sure to fold the corners down or tape the outside layers together to prevent the bag from falling apart. Select large decorating tips. You'll need one of these metal decorating tips or nozzles so the frosting comes out evenly. Make sure to use large or jumbo nozzles if you want to create a typical cupcake swirl. Regular sized nozzles, or a tiny hole in the bag with no nozzle at all, can create intricate designs but not the thick, decorative swirls used for most cupcakes. You might be able to find the most common large piping tips, the Wilton brand 1M and Wilton 2D, at craft shops. If you want to try different types of swirls, you may need to find other tip designs in online stores. Tips with round holes produce a design that looks like smooth soft-serve ice cream. Star-shaped holes make rippled or ruffled swirls, and you can buy them in many designs depending on which pattern you like best. Use a tip coupler if you plan on switching between multiple piping tips. Tip couplers are screwed around the bag so you can easily remove one tip and switch to a different tip design. First drop the smaller ring section into the bag, then screw the larger ring onto it from the outside of the bag, holding the bag in place. A piping tip can slot into the outer ring and easily removed when it is time to switch Use a large-sized tip coupler to match the large piping tip. The tip should slot easily and firmly into the coupler. If you are only using one tip, place it directly into the bag. Point the decorating tip nozzle downward and push it to the narrow end of the bag. The nozzle should poke through the hole in the end but be held in place by the walls of the bag. Cut a larger hole if necessary, but don't worry if it's not a perfect fit; the icing should hold the tip in place. Place your piping bag in your cup or mug. Put the bag nozzle-side down into a tall cylindrical container. This will steady the bag while you fill it with frosting. If you're using a plastic or canvas bag, you can fold down the edges outward for easier access to the base of the bag. See the Tips section for a less messy method of filling your pastry bag using plastic wrap. Spoon the frosting into the piping bag. Frosting is the right thick consistency for a pastry bag, whereas icing is thin and liquid based, and might run through the nozzle before you squeeze. Either way, filling the bag is likely to create mess, so go slowly. If the spoon is making a mess or the frosting keeps sticking to it, try using a spatula instead. Gently press down the frosting as you go. Continue to fill up the bag, pressing the frosting lightly against the bottom of the bag to remove air bubbles. If you don't pack the frosting firmly enough, you will have gaps and unsightly air bubbles in your frosting. Roll up the folded edges of the bag bit by bit whenever you need more room for frosting. Do not fill the bag too full, especially if it's a delicate parchment paper bag. You'll need some room to tie it off and squeeze. An overfilled bag is difficult to control. Twist the top end of the bag. Twist and hold the top end of the bag so you can squeeze it without frosting flying out the top. Try to twist right above the frosting to minimize the amount of air that might get mixed into it. You're now ready to move on to the decorating. For greater convenience, use a rubber band to tie it shut. Try practicing on a plate first. If you've never used a piping bag before, you might want to begin with something less important than your beautiful cupcakes. First practice by following these instructions over a plate or piece of parchment paper. If you'd rather get started sooner, you might still want to squeeze a short line of frosting out on a plate so you can get past any air bubbles trapped at the bottom. The instructions below remain the same whether you're decorating a cupcake or just practicing on another rounded or flat surface. Squeeze most of the frosting to the top of the bag. Make sure the top of your bag is tied or twisted as described in the last section. Push most of the frosting up to the top of the bag until you're left holding a small handful of frosting at the base of the bag. Twist the bag above this amount so the rest of the frosting doesn't fall through. Now you only need to squeeze a much smaller, more manageable amount of frosting. You'll be able to decorate for longer without your arms tiring, and you'll have more control over your decoration. Warning : Do not attempt this with a parchment paper bag. It will fall apart or break. If you find the parchment paper bag tiring to use, try filling it only half full of frosting or less. Untwist the bag and push additional frosting to the lower area whenever you start running out of frosting. You should have enough frosting in that handful to decorate at least one cupcake. Learn how to hold the bag. You will be using one hand to hold the bag upright and squeeze out the frosting, placing it around the handful of frosting you just separated from the rest. Use your other hand to guide the bag. You can guide the bag by grasping the top of the nozzle and pushing it like a pencil, or by holding your first hand and helping it to move steadily and evenly. Some people find it easier to hold the bag with the dominant hand, while others prefer to use the non-dominant hand. Try out both methods to see which one feels more precise. Hold the bag vertically above the cupcake. The nozzle of the decorating tip should be between 1/4 inch (1.25 cm) and 1/2 inch (2.5 cm) above the surface you're decorating. You can try lifting or lowering it by tiny amounts to see which distance creates the most attractive design, but don't push it against the cupcake's surface. That will most likely create a smeared or sloppy looking design. If you are decorating a cupcake with a special shape, or the side of a cupcake, keep the bag at a 90º angle to the side it is decorating. The bag should be horizontal when decorating a vertical surface. Squeeze the icing bag over the center of the cupcake. An even squeeze with the hand around the bag should produce a dot or star on the cupcake's surface, depending on which design of piping tip you are using. The squeeze should be slow and even, but hard enough to produce a steady flow of frosting. Read the next few steps before you begin so you know where to move the piping bag. Piping in one motion will make your design even and attractive. Continue to squeeze as you spiral around the center of the cupcake. Maintain the same pressure on the bag to deploy the frosting at an even rate. Without lifting the bag, circle tightly around the central frosting dot until it is completely surrounded. Don't leave any space between the circle and the central dot. If your cupcakes are large or your piping tip is small, you can spiral outward to create a second circle around the first. It's easier to make a stable swirl if you don't go too near the edge, however. Continue to squeeze as you spiral inward and upward. When your circle is finished, move the piping tip higher up and slightly inward. Spiral inward to create a smaller circle on top of the first. Complete the spiral by moving the piping tip inward to the center. Again, maintain a steady pressure on the bag and guide the piping tip at the same, steady rate. Stop squeezing and gently lift the bag. It's important to release all pressure from the bag before lifting it from the cupcake. If you stop squeezing, then lift the bag in a vertical line, your swirl will end with an attractive decoration. This will be a star shape of some kind for most piping tips, or a small point for simple, round piping tips. Try these simple variations on the basic swirl. There are several variations of the basic cupcake swirl described in the Piping the Cupcake section. They have slightly different appearances and use different amounts of frosting, but don't require any additional techniques. Start near the outside edge instead of at the center, and spiral inward and upward. This looks almost identical to the basic swirl, but is easier to pipe on a small cupcake. Start at the center and spiral outward. Stop when you complete a circle near the outside edge. This uses less frosting and creates a flat rosette design. Use a French tip nozzle to create a quick and unique design. A French or French swirl piping tip design deploys the frosting in high, thin ridges. You can hold the bag still above the center of the cupcake, then squeeze as you watch the frosting spread evenly outward on top of the cupcake. This technique works best on small cupcakes, since the frosting won't spread out evenly past a certain distance. Use a petal tip to create a flower. A petal piping tip has a thin, teardrop shaped nozzle. This is more difficult than the standard cupcake swirl method, and works best if you hold the bag at a 45º angle from the cupcake's surface. Keep the nozzle vertical with the wider end nearest the cupcake. Spreading a small amount of frosting over the cake with a knife might help keep your petals from falling over. First squeeze while moving in a tiny circle a the center of the cupcake to create a cylinder of frosting. Stop squeezing, then move the bag away. Squeeze the bag just long enough to deploy frosting in a small U shape, with the bend of the U resting against the cylinder. Move the bag up as you reach the bend of the U and down again as you move to the other leg of the U. Continue making U shaped petals outward in a spiral pattern until you cover the cupcake in petals. Remember to stop squeezing before you move the bag between making petals. Use multiple bags of icing to create multicolor swirls. You can use this trick with any piping design to create a swirl of two or more colors. You'll need three or more plastic or canvas pastry bags, not temporary parchment paper ones. A large tip and tip coupler (see Preparing to Pipe) will make this much easier. For best results, use different colored frosting of the same type, not completely different recipes that may squeeze out at different speeds. Put each color frosting into its own bag. Only put a small amount of frosting in each, no more than 1/2 the usual amount at most. Tie or twist each bag as usual. Flatten each bag of frosting and stack them on top of each other. Press down to get a triangle shape and place each bag on top of the last. Cut off the bottom 1/2 inch (1.25 cm) of each bag. If there's already a hole large enough to squeeze a line of frosting through, you can skip this step. Place the stack of bags inside a larger bag with a piping tip attached. Push the stack of bags evenly to the bottom. Now, when you squeeze the larger bag, each bag inside will squeeze out a different colored line of frosting through the piping tip. 
Make the frosting right before you're ready to pipe. Buy a piping bag or make your own. Select large decorating tips. Use a tip coupler if you plan on switching between multiple piping tips. If you are only using one tip, place it directly into the bag. Place your piping bag in your cup or mug. Spoon the frosting into the piping bag. Gently press down the frosting as you go. Twist the top end of the bag. Try practicing on a plate first. Squeeze most of the frosting to the top of the bag. Learn how to hold the bag. Hold the bag vertically above the cupcake. Squeeze the icing bag over the center of the cupcake. Continue to squeeze as you spiral around the center of the cupcake. Continue to squeeze as you spiral inward and upward. Stop squeezing and gently lift the bag. Try these simple variations on the basic swirl. Use a French tip nozzle to create a quick and unique design. Use a petal tip to create a flower. Use multiple bags of icing to create multicolor swirls. 