What you should do instead: Using your opposite hand, pull your underarm skin taut and shave in an “X” pattern. This will get you the closest shave possible while reducing irritation.
Why this works: While the hair on your arms or legs tends to grow in one direction, the hair under your arms grows in a swirl pattern (aka in all different directions). By shaving in an “X” pattern, you’ll catch more hairs while reducing the number of swipes you make across your skin. So the next time you go to shave your pits, remember: “X” marks the spot.