Using dpns for the top of a hat is one of best introductions to dpns and the easiest. Just knit about 1/3 of the stitches onto each needle, exact numbers don't matter. I like to put a decrease right at the end of a needle, but you don't have to. The hardest part about dpns is getting started and the hard part is avoided in this use. Also knitting a very few stitches on dpns is harder than more. A sock's worth or a fingerless mitt isn't that bad, if you try to begin with only 3 stitches it is trickier. I like to cast on all the stitches to one needle and then divide them up.