If you have a store card that doesn't get used frequently, I'd suggest paying the charge as soon as it posts, especially if it's a low amount. That way, you don't have a chance to forget, and the bill is out of your hair.
Another good habit is to log into each of your credit card accounts periodically just to make sure things are OK, i.e. no unexpected charges, fraud, etc.
And as others have said, set up any alerts that are available to you.
