Mina,
I've always found that a quick spritz of spray starch and touching an iron to the points to "crease-in" those points before pinning them to the fabric helps me. Trimming a hair closer and making the small allowance even a bit smaller on one side sometimes helps, too. Practice was what really worked for me, though.
I like my points really, really pointy and spend a lot of time on them. A girlfriend of mine is not so picky and doesn't mind a little bit of rounding, you just have to decide what you can live with.
Shelly