I finally got desperate enough to attack my hair with scissors. Didn't come out half bad. and no, I'm not brave enough to post a picture.
After yet another 'cut way too short' haircut a long time ago now, I stopped getting mine cut. I quickly worked out how to cut my own hair. It might not look like a layered cut, but it's ok, and I never did care about hair shape.
It helps if you have a mirror system which allows you to see both sides of your head reflected from another mirror. Mirror doors on cabinets are really good for getting the perspective better.
But once you figure it out, you wonder why we bought into the need for professional hairdressing in the first place. Especially when they never do it the way you ask them to.
With practice, you can get by with just the one bathroom mirror. You can cut the back by feel.
I stopped paying for haircuts in 1997. Been cutting it myself ever since. I use clippers for the sides and scissors for the top.
Advice for y'all attempting this for the first time: Always cut off less than you think you should. You can always go back and remove more hair, but you can't put that hair back on. Better to make several passes that end up looking good than to make a single pass that butchers it. The first few times you cut your own hair, it might seem like it's taking forever, but you
will get faster with practice, I promise. Also, stick a wadded-up half-square of toilet paper in each ear before you start. If you don't, the little hair pieces will get in your ear and increase the wax buildup.