I started cutting hair when my brother decided to risk letting me try on him. Mom just couldn't do what he wanted to it anymore. I seemed to have a knack for it. I actually really enjoy cutting hair, though my haircuts do take a long time. Gibbie's first haircut sure wasn't stressful or traumatic, as it happened right in our living room. He seemed delighted to sit still for me, and be the center of my attention.
I've noticed a lot of moms who cut their own kid's hair have trouble doing anything than cutting straight across. I picked up layers and thinning by watching closely when I went to a professional (as my own hair was cut, and around at the other chairs). Library books helped confirm my ideas. That, and having a family willing to sit patiently for 45 minute cuts. Eventually, I had the confidence to try cutting friends' hair as my own family got compliments. We keep a little box in the linen closet with a smock, good scissors, combs, clippers, hairclips, and thinning shears.
You can put cut hair in the compost bin or give it to the birds for their nests, if it's not long enough to donate to Locks of Love.