With all the knowledge, experience, and ingenuity represented on this board, I imagine we could have a VERY informative thread if we were to share a trick or two we learned or figured out over the years that made photographing easier or better. So I'll start:
1) All Caucasian faces go on Zone VI every time. I use the zone system or some bastard varaiation of it in all other cases, but this rule seems to have never failed me. Kind of goes along with "eyes always in focus".
2) I use the Jobo Expert drum on a Beseler base. It used to "walk" off the base slowly...I thought I would have it leveled, then 5 minutes into development it would tip. I fixed it with rubber bands that show me easily and from a distance if it's walking or not.
3) I realized that it is your heartbeat that makes it so you can't shoot a handheld camera slower than about 1/30th or maybe 1/15th. I noticed that if you relax while holding the camera you can actually see it going up and down with every heart beat. If you get your timing right, you can shoot at 1/8th at the rest between beats.
Not the best, I know, but I am hoping you'll top mine...