How to squeeze some EV out of your sessions
Since improving your performance in general isn't something that's touched on a lot here, I figured I'd throw in a few suggestions on how you can pick up some extra EV out of your sessions in hopes that other people will chime in as well.
1. Take a period of 5-10 minutes to sit and relax without doing anything before your sessions. This collects our focus, and is a useful habit to get into since it can help our performance in all sorts of activities.
2. Every 60-90 minutes or so stand up, stretch and evaluate how you're feeling and how "together" you are mentally. This brings us back into the present moment which is the cure for a lot of blunders that happen at the table.
3. All of your sessions have something in common: they have an end. Work on ending your sessions well, meaning that you don't wait until you're playing bad or feeling tired to stop -- you should quit a little while before either of these things happen to help avoid tilt-related mistakes.
On a more personal level, I find that talking to people while I play allows me to play longer without getting tired and makes me play better since I'm always throwing hands in the mix for immediate feedback. During my sessions I always have #flopturnriver, Skype, Ventrilo, and/or instant messengers going.