For me, writing helps a LOT.
I mean, you have all this excess emotion going on (mood swings, etc) so why not put it to use? I've found I've written some amazing things during heavy PMS cycles, and when I read it later on sometimes it doesn't even sound like me.
Also, it's really really hard to give in to cravings when you're concentrating so hard on what you're writing, and it's too messy to eat and write at the same time.
I don't think it really matters what you write, but if you make it something personal, it can really pull all that icky stuff like crankiness out of you onto the paper.
Ooh, and I find eating salmon alot prior to my cycle helps as well. I had no idea why, but I did a little research and found this (lucky us, most things look legal! Not all, but enough to make me happy.)
http://www.wholehealthmd.com/hk/reme...59,502,00.html