Reminders are good. Learning new things is good. So you might look at this list, of 21 Ways to Shoot Better Photographs, as either a list of reminders or a list of new things to learn. Either way, it is good.
I think the most important ones, for me, are perspective, framing, intentional empty space, and the horizontal line. Everything else seems to fall into place once you follow those few things and really begin to see your photographs before you snap.
Source: 21 Ways to Shoot Better Photographs 10e20 Blog
Via: Jason Kottke.