My only tip's probably fairly obvious. I change my password every couple of weeks, and try to keep it as varied as possible. I have a friend who's obsessed with password security. His password for most things is huge, and he keeps a folder with a series of questions in it. The answer to each one is another part of the full password. It's mind-boggling. Wouldn't recommend that level of security (a bit paranoid in my opinion), but still. The simple things help!