Pimples can form when sebum gets blocked in pores by dead skin cells in hair follicles. Bacteria grows inside the follicles, which then rupture near the surface and form whiteheads or blackheads. You should not touch or irritate acne-prone skin, and this can make shaving acne-prone areas like the face and chest difficult.
Wash your chest with warm water. Sitting in a hot bath can be helpful, as it allows your hair follicles to open up. Soak your body for at least three minutes to soften your skin.
Apply a pre-shave oil such as jojoba oil. Acne.org suggests this helps to further soften skin and prepare it for a close shave.
Trim any extra hairs that are too long to shave with a small pair of scissors.
Use a quality, nondisposable razor with a sharp blade. Apply a water-based shaving gel for sensitive skin. Always shave in the direction of hair growth, and stretch your skin to pull it taut for a closer shave.
Wash the gel and hair off generously with warm water. TeensHealth suggests finishing off the rinse with cold water to close off pores.