How to Have a Smooth Underarm Shave
If you want a smooth underarm shave, start by rubbing a mild exfoliating scrub under your arms. This will bring the hair closer to the surface for a better shave. Then apply shaving gel to your damp underarms. Next, stretch the arm you're shaving as far over your shoulder as you can to pull the skin tight. Finally, work the razor in the direction the hair grows to get a smoother shave.
Apply an oil. Moisturizing the skin under your arms plumps it up, so there's less likely to be irritation when you shave. Instead of a regular moisturizer, though, you want to use something that offers more intensive hydration. That's why it helps to apply an oil at least 24 hours before you plan to shave. You want to give the oil enough time to fully absorb into your skin. Make sure to use a rich oil, such as argan or olive oil. It's best not to use coconut oil because it's so lightweight that it absorbs too easily into the skin. The oil that you apply may come off on your clothing, so be sure to wear an old shirt that you don't mind staining. You may prefer to apply the oil to your underarms before you go to sleep when you'll only be wearing pajamas. Shave in the evening. You probably shave whenever it's most convenient in your schedule, but choosing the right time to do can help you get a smoother shave. Shaving removes several of the skin's protective layers, so it may be more easily irritated and prone to infection afterward. Doing it at night is the better option because you can give your underarms time to calm down before you start applying deodorant and other personal care products in the morning. Shaving your underarms at night usually allows you to take more time with the process, which means you're less likely to rush and make a mistake. If you notice that your underarms have a reaction to your deodorant, body spray, or perfume after shaving, it's especially important to shave at night when you don't use those types of products. Exfoliate the area. Whenever you shave, it's a good idea to exfoliate first to remove dead skin cells. That helps bring the hair under your arms closer to the surface so you can get a closer shave. Use a mild exfoliating scrub or some body wash on a washcloth to gently exfoliate your underarms before shaving. When you're applying the exfoliator to your underarms, use circular motions, making sure to cover the entire area. If you prefer natural body products, you can create your own body scrub for the under arms by mixing 2 tablespoons of brown sugar, 1 tablespoon honey, and 1 teaspoon lemon water. Dampen skin. Before you pick up a razor, it's important to dampen your underarms. Splashing them with warm water not only helps plump the skin, but it can actually help soften your underarm hair, so it's easier to cut. The easiest way to wet your underarms is to shave while you're taking a shower. Shave at the end of your shower. That gives the moisture and heat plenty of time to soften your skin and hair. Apply a shave gel. While moisturizing your skin ahead of time can help give you a closer underarm shave, you'll need extra lubrication to ensure that the razor glides over the skin. Apply a moisturizing shave gel or cream to your underarm area. Because the shave gel helps the razor move easily across the skin, you need to use less force to cut the hair, which means you'll have less irritation. If your underarm area is prone to irritation, be sure to choose a shave gel or cream that's formulated specifically for sensitive skin. Choose the right razor. For the smoothest shave under your arms, you want a sharp razor, so be sure to change yours regularly. It also helps to use a razor that has multiple blades and a pivoting head when you want a close shave. Some razors are actually designed specifically for the underarms, so read the packaging carefully. To ensure that your razors are sharp and clean, replace them after every four or five uses. Look for a razor with a rubber handle that's easier to grip. That allows you to follow the contours of your underarm area more easily. Pull the skin tight. When you're ready to move the razor over your underarm area, it helps to make the surface as smooth as possible. Try to pull the skin as tautly as you can, so there are no wrinkles or creases for the razor to skip over. It can be difficult to pull your skin taut when you only have one hand free as you're shaving. To pull the skin tighter, stretch the arm that you're shaving as far over your shoulder as you can. Use the correct motions. For the closest shave under your arm, it's important to move your razor in the right direction. Underarm hair doesn't grow in a single direction so you need to move the razor in multiple directions to get the smoothest shave. Start by working the razor in a downward motion over the underarm. Next, move the razor from one side of the underarm to the other. Be sure to move the razor as firmly as you can. If you use too light a hand, you can wind up slipping and cutting yourself. Shaving against the grain of hair growth gets you the closest shave. However, if you have sensitive skin, you should avoid going against the grain because it can cause irritations. Rinse the razor often. Each time you move the razor across your skin, it picks up shaving cream, hair, dead skin cells, and other debris. Leaving all of that on the blades can make it more difficult for the razor to cut the hair, so you don't get as close a shave as you'd like. Rinse your razor with hot water after every stroke if possible. Shaving with a dirty razor can also spread bacteria, which may cause an infection or other irritation in your underarm area. Moisturize your underarms. Shaving your underarms can leave the skin tender and slightly irritated. The best way to help soothe and condition your skin is to apply a moisturizer after shaving. It's best to use an unscented body lotion or cream to prevent irritation. However, you can also use coconut oil if you prefer natural skin care products. Some deodorants contain moisturizing ingredients, such as avocado oil, sunflower seed oil, or glycerol, so you can eliminate the need for a separate moisturizer for your underarms. Avoid deodorants that contain harsh ingredients, such as alcohol or dyes. They can irritate your skin even if you use a moisturizer. Use an anti-razor bump treatment. If you're prone to ingrown hairs in the underarm area, try to prevent them before they happen. There are a variety of products designed specifically to fight ingrown hairs or razor bumps that you can apply after shaving. Typically, they contain exfoliating ingredients, such as salicylic or glycolic acid, that remove dead skin to prevent the hairs from becoming trapped beneath it. If you have sensitive skin, it's best not to use a leave-on product under your arms. Instead, use a body wash that contains salicylic acid on the area. You rinse it away, so it won't sit on your skin too long and irritate it. Wear the right clothing. If your underarm area is bumpy and irritated after a shave, the clothes that you're wearing may be a factor. Tight shirts and dresses that are made of synthetic fabrics have a tendency to trap sweat and dirt, encouraging the growth of bacteria that leads to a rash or other irritations. Instead, opt for loose-fitting clothing made of breathable fabrics that allow air to circulate in the area. Breathable fabrics include cotton, linen, and chambray. Make sure to wash your underarm area every day to prevent the growth of bacteria. 
Apply an oil. Shave in the evening. Exfoliate the area. Dampen skin. Apply a shave gel. Choose the right razor. Pull the skin tight. Use the correct motions. Rinse the razor often. Moisturize your underarms. Use an anti-razor bump treatment. Wear the right clothing. 