If you crochet a ring of 2 or 3 sts, then st 1 ch 1 every row, you will have a flat circle. One way to make a hat is to first measure how many sts go around your head, then make a flat circle until you reach the predetermined number of sts. Once it's big enough, don't increase anymore, just keep crochetting singles or doubles, or whatever you want, until it is long enough! That's a pretty easy way. Good luck!