Plan your workouts ahead of time, know what you're going to do, get to the gym and get out as quickly as possible. Write the exercise and estimated weights in the exercise column based on your last workout. Gauage how hard it was to decide whether you need to step it up for the next time in the gym.

For more details see my blog post on the topic. If there's intrest, I'll post the OOo Draw file so anyone can make "hard-coded" version of their workout for themselves.