How many stitches are you starting with? For a rounded top you should be doing about 8 or 9 decreases per round, for a pointy top you will be doing less than 4 per round, and for a flat top (beret or tam style) you will be doing more than 9 per round. Also, you might want to stop doing the knit rows in between decreases as you get closer to the end.
IOW the fewer decreases per round the pointer the hat will be.
I'm Cassique on Ravelry