When I decided to try cutting my own hair, I turned to youtube, and have tried various methods to get a straight cut, but haven't been successful. Layers were the big hairstyle when I was a teenager, and I have an involuntary horror of that time period; I saw a woman older than me dressed in the current 80s throwback fashion, and I could only think: you lived through it the first time, you should know better!
But yeah. Haircuts. Since I couldn't do a straight cut myself, I decided I would rather be a pathetic 90s throwback than go to the hairdresser (top tip for ladies who hate hairdressers: go to the barber instead--quicker, cheaper, and no forced chat about your personal life). I now cut my own hair about once a year, using the ponytail method.
I have medium length hair, and to be honest I much prefer short hair, pixie style. Except short hair doesn't stay short and I don't have the inclination (or patience) to maintain it myself.