How can i trim my hair decently?

i have buzzers(clippers etc.) and a few sizes

most importantly, because my hair is so long

i was just going to use a size 4 and was wondering if it would function like a flowbee, ;)

in other words cut my longer hair but pass by shorter hair

just to experiment with

i figure i could just get it done, but the summer time would be a good time to experiment and if i do a terrible job i can just cut it all short and wear my hat

anybody ever done this?

How can i trim my hair decently?

just ask a local barber can he/she do it