How to remember not to talk too much?

I keep getting into arguments with my roommate. I think it would be better if we didn't argue, since I'd rather have a good relationship with her, and I don't want to have to find somewhere else to live.

I can stop myself from responding to the things I want to argue about for a couple of days at a time, but after awhile, I forget and fall back into my old habit of arguing again.

How can I remember not to talk when she starts talking about things I want to argue about? Is there a good method for changing the habit of talking and/or arguing?