I used to cut my hair (and my friends') as an undergrad, so I picked up a clipper about 9mo ago and started doing mine again (and my son's, if he'll hold still...). It's fine, I rarely get it perfect on the first go, but I just tidy up the next day. The clipper cost less than a single trip to a barber...
You still need to make a clean line at the back and do around the ears. If you don't it looks really sloppy. Definitely something you can learn, but it's not as easy as just running the buzzer over your head.
If you want to get your moneys worth for a buzz at the barber ask them to fade or taper it.
I've tried, but it's not worth it. DIY is more difficult, you need more than one mirror, you have to clean all the hair, and it definitely takes more of your time. I have the blades but only use them for the beard.
If it's a #2 all over you'll have no problem finding the remaining patches with your hands. No mirrors needed, just feel your head. This is true for most guards about #4 and below. Above that and the length of the hairs are not different enough to feel the differences.
