Clean your underarms thoroughly. Wash them with soap or a good body wash, and scrub them a little to exfoliate the skin.[1] If you use hot water, the hairs and surrounding skin will soften, making the hairs easier to remove.
Trim the hair. If the hair under your arms is longer than 1/4 inch, you should trim it with a pair of barber or nail scissors until it's 1/4 inch long. This makes the waxing process less painful.
2
Wrap yourself up in an old towel. The wax is bound to spill and create a mess when you try to do it yourself, so it's best to be either naked or wrapped in something you don't mind getting sticky with wax.