How do you buzz your own head?

I hate going to the harbor shop, mostly because I don't want to pay money for something that will grow back and I will have to pay money again. A friend of mine who has moved, would cut my hair since he was good at it, and when I swam I would use a 1'; on my clippers and just go all the way. Well my girlfriend doesn't like when I do that, she says I look like a badass and she don't like that, go figure I thought girls like bad boys. O well I' am not too much into impressing any girls, I just need to clean up my head a bit, cause its a mess. How do you go about cutting it your self? I've done it before, using like a 4 or a 5, but I always wanted to know what would happen if I would go with a five all around, and then a 4 in a back of my head, and then down to 3 near my neckline?How do you buzz your own head?
4 or a 5? thats not buzzed! 1 or a 2 is buzzed. I always cut my hair like that (buzzed). Ive cut my hair a few times and its not that hard unless you dont have mirrors then it will be hard. Harder is to do the edge-up especially in the back. i suggest just go to get it cut. it saves all the time and work