Something I have begun doing recently when staring at a bunch of models on my painting table is create a list of how to paint them. Scratching items off the list helps feeling like you've accomplished something - even if it's just a wash and doesn't make much difference in how complete the model looks.
At first I would just do this once I get down to the nitty-gritty details, to make sure I didn't miss anything - however I took it a step further with the goblins I recently completed since I had a deadline and not lots of time to meet it. Here I planned out the exact colours and order of painting to be most efficient. It worked really well and additionally I can use it when painting the next batch from the same army to ensure they look cohesive.
I think it's time to scam Admiral Drax's notebook idea, and keep lists for all models I paint. That way I always have something to reference and even months or years from now could reproduce the paint job if adding models. Currently thinking of my undead blood bowl team for when I manage to get a couple more zombies and maybe another ghoul.
Any of you guys have other "non" painting tips for me?