i cut my own hair as well as my son's. my mother is a hair-dresser and i grew up getting a lot of haircuts i didn't like, so i started doing my own in high school. here are my tips:
1. grab your balls and commit. whether using clippers or scissors, it's going to take time and patience.
2. mirrors and lighting. if you're fortunate enough to have one of those bathroom layouts with the mirrored medicine cabinet caddy-corner to your main mirror, you're ahead of the game. otherwise, pickup a cheap handheld barber-style mirror. if you have someone willing to hold it for you throughout the process, use them. treat them kindly. bring in a bright desk/floor lamp if you need more light.
3. check your progress intermittently. check all angles with your mirror. sit on the countertop closer to the mirror, move your lamp around to catch different angles, remind yourself repeatedly of your giant pendulous balls. play some ghostface. find what works for you.
most cuts are very easy. like anything else you do yourself, whether grinding and brewing your coffee at home or pressing your own clothes, it's very satisfying when you're successful. if you screw up it will grow back and most people will never notice. i sometimes go back over it again a few days later and catch something to correct.
if this sound too much then don't try.