Very carefully. You will need two mirrors and it will not be easy and you will not know for sure if you don’t have it because of how difficult it is to check yourself for lice.  Use a wall mirror and handheld mirror, or two handheld mirrors, and check your scalp along your neck, around your ears, and along your hairline.

It is better to pay for an affordable lice check by a professional and know for sure than to spend your time checking and worrying about lice.