How to Make Shorts
To make a pair of shorts, start by folding a pair of you shorts you already own in half and tracing the edges onto crafting paper to make your pattern. Add an inch around the bottom and sides before you cut out your pattern to make space for the seams. Pin the second piece of material to the first piece and cut around the edges with sharp sewing shears. Then, repeat the process to make a second, identical piece of material. After you've cut out your second piece of material, pin it to the first along the seams and stitch them together. When you've finished the seams, open your material up and sew the inner seams and hems.
Make your pattern. You can make a simple, quick pattern for your shorts by tracing the outline of a pair of shorts that fit well on a piece of craft paper. Fold your shorts in half. Make sure that the front pockets are on the outside. Trace the outline of your folded shorts on craft paper. Add 1 inch (2.5 cm) around the bottom and sides of the pattern for a seam allowance. Add 1.5 inches (4 cm) to the top of the pattern for a waistband. Cut the pattern out with scissors. Pin the pattern to your fabric. Fold your fabric in half and lay your pattern out on top. Pin in place. The long side or center of the pattern should be placed along the folded edge of the fabric. For a more accurate approach, sketch the outline of the pattern onto your material. Cut the material out. Use sharp sewing shears to cut along the outline. This will create one full side of your shorts. Repeat. Make another piece for your shorts using the same pinning and cutting method used for the first piece. Fold your fabric in half and lay your pattern out on top, with the long side of the pattern along the folded edge. Pin in place. Cut around the pattern to form another piece. Pin along the seams. Unfold your two pieces and line them together with the right sides facing each other and the wrong sides facing out. Pin together. More specifically, pin along the two rounded seams of each piece. These seams are the ones you will be stitching together next, so keeping them evenly aligned is essential at this point. Stitch the seams together. Use a sewing machine to sew along the rounded seams. If sewing by hand, use a backstitch. Allow for a 1 inch (2.5 cm) seam allowance. You should be left with what appears to be a single connected "tube" of fabric. Flip the shorts over. Turn the fabric over so that the stitched seams sit in the center front and center back of the fabric. After sewing the two separated pieces together, the sewn seams will be on the outside edges. You'll need to rotate the shorts so that these seams are down the vertical center and evenly aligned with each other. These sewn seams will end up forming the crotch of the shorts. Sew the inner thigh seams. Flatten the fabric so that the opening below the center line of the crotch can be seen easily. Pin along both sides of this material and sew together to complete each leg. Use seam allowance of 1 inch (2.5 cm). Sew these sides together using a zig-zag stitch. These seems will fall out along the inner thigh. Create a waistband. Fold over the upper edge of the fabric, leaving enough room for your elastic band. Pin in place, then sew along the raw edge to stitch the waistband down. Fold over the top 2 inches (5 cm). This should give you enough room for the waistband elastic. Sew a straight stitch with your sewing machine or a backstitch by hand. Leave a small hole along the seam so that you can thread the elastic through it. Feed the elastic through the waistband. Insert the elastic through the opening in the waistband and push it along the waistband until it reaches all the way around. When done, sew the opening in the waistband closed. The elastic should be about the same size as your waist, minus roughly 3 inches (7.6 cm). Since elastic needs to stretch to stay secure, this extra space will make sure that the shorts stay snug on your waist. Clip a safety pin to one end of the elastic to make it easier to feed the band through. Alternatively, tape the elastic to a long chopstick to make it easier to feed through. Pull both ends of the elastic through their respective openings along the waistband. Hold them taut as you zig-zag stitch the elastic together and the opening closed. Hem up your shorts. Fold up the bottom edge of each leg by about 1 inch (2.5 cm). Pin in place and sew around the leg opening to create a hem. This completes your shorts. Use a seam allowance of about 1/2 inch (1.25 cm). Make sure that you do not sew the front and back of the shorts together. You need to sew the hemmed fabric around the opening of the leg. When done, turn the shorts right-side out again and try them on. Download a pattern. The quickest, easiest way to make a pair of boxer or athletic shorts for men is to download a free pattern online. You can find the pattern used in conjunction with these instructions here: http://www.craftpassion.com/wp-content/uploads/PDF%20Pattern/Boxer%20Short%20Pattern.pdf As you print the pattern out, set the printer for A4 paper and do not check the "scale printing" box. Follow the instructions on the pattern to piece everything together. Each corner is labeled with numbers, and you can create the full pattern by matching these numbers together. Cut the patterns out and tape them together at the appropriate places. Pin the material to the pattern. Place the pattern on the wrong side of the fabric and pin in place. For added accuracy, use a piece of chalk or sewing pencil to sketch an outline of the pattern onto the wrong side of the fabric after pinning the two items together. Note that the seam allowance is included in most patterns, included the one provided here. Fold the lining fabric so that it becomes a double layer. When pinning the waist band lining, pin the pattern with the "fold" marking lined up with this folded edge. Cut out the material. Cut along the sewing lines until each piece has been cut out. Use sharp sewing shears for this. Cut the pieces out in reverse order. In other words, the last piece you need should be the first piece you cut out, and the first piece you need should be the last you cut out. This way, as you stack the pieces together, you will end up with the first piece on top of the stack. Prepare and stitch the two back pockets. Pin the pocket pieces onto the correct portions of the shorts pattern as marked on the patter itself. Use a double top stitch to sew the sides and bottom of the pocket in place. Use an iron to press all four edges of the pocket pieces. Before pinning the pockets to the shorts fabric, double top stitch the top hem of the pocket. This edge will be the pocket opening. After doing these two steps, you can pin and sew the back pockets in place as described. Prepare and stitch the two front pockets. The method used on the front pockets is the same as that used on the back pockets. Use an iron to press all four edges of the pocket pieces. Before pinning the pockets to the shorts fabric, double top stitch the top hem of the pocket. This edge will be the pocket opening. Pin the pocket pieces onto the correct portions of the shorts pattern as marked on the patter itself. Use a double top stitch to sew the sides and bottom of the pocket in place. Sew the crotch. Pin the back portions of the shorts fabric together and sew along the crotch portion of the pattern. Pin the pieces together with the right sides facing each other. Trim one side of the seam to 3/8-inch (9.5 mm) using sharp sewing shears. Clip curve the bottom of the crotch seam, as well. Use a flat felled seam to sew the crotch seam up. Stitch up the rest of the seams. Sew the inseam and the side seams with the right sides of the pieces facing each other. After sewing the inseam, serge or overlock the raw edge to prevent excess fraying. To sew the side seams, use a flat felled seam method. Hem the shorts. Fold the bottom hem up and use a double top stitch to hold it together. Press the bottom hem with an iron to create a sturdy fold. Sew the waistband lining. Stitch the waistband lining to the waist with the right sides facing each other. The joint of the lining should line up evenly with the center of the back waist portion. Sew the elastic waistband together. Zigzag stitch the raw ends of the elastic together, overlapping the edges by about 1/2 inch (1.25 cm). Make sure that the elastic will fit snug on the wearer's waist. Measure around the wearer's waist. Take this measurement and subtract 3 inches (7.6 cm) from it so that the elastic band has room to stretch out. Fold the elastic into the lining. Pin the elastic into the lining and fold the material over the band. Sew it closed to complete the shorts. Pin the elastic to the center of the back waist. Fold the band in half, and pin it to the center of the front waist. Divide the band into a few other equally spaced points along the lining, pinning it to the fabric in another eight to ten places. Fold the lining edge in the band with the wrong side facing out. Sew along the edge while stretching the elastic band gently. Turn the shorts so that the right side faces out. Gently stretch the elastic and double top stitch about 1/4 inch (6.35 mm) away from the top and bottom edges. 
Make your pattern. Pin the pattern to your fabric. Cut the material out. Repeat. Pin along the seams. Stitch the seams together. Flip the shorts over. Sew the inner thigh seams. Create a waistband. Feed the elastic through the waistband. Hem up your shorts. Download a pattern. Pin the material to the pattern. Cut out the material. Prepare and stitch the two back pockets. Prepare and stitch the two front pockets. Sew the crotch. Stitch up the rest of the seams. Hem the shorts. Sew the waistband lining. Sew the elastic waistband together. Fold the elastic into the lining. 