lol it's very simple, like trimmin' your shlong, you wanna cut as much leaf as possible while not knicking the bud, understanding the basic structure of a bud take a little time but you learn to take the fan leaves first, by cutting the extending stems,usually into a bag for compost, then trimming the smaller leaves flush to the bud into a seperate collection recepticle for later prosessing into kief or hash.
if you don't want to save any scrap for reprossessing then just wait till your buds are mature and cut off everything flush to the dence flower mass and once they dry and shrink you will see the common shape of street bought buds, leaves lose more mass than buds as they dry.