I've developed a set of stead-fast rules with my photography and I'll share them with you here. If you have to ask why, you're breaking rule 9. Rule 9 is never question why? Also, all rules are made to be broken. Never say never and always question your own logic...
So, if you have a good rule you'd like to share or want to tell me how stupid my rules are, let's hear it.
A work in progress and In no particular order.
1. Always take the lens cap off.
2. Always bring an extra battery.
3. Always keep a speed-light in your kit.
4. Never photograph the south side of a northbound animal.
5. Always look behind you. You never know what you're missing if you don't.
6. Always shoot RAW.
7. Always keep a lens cloth with you.
8. Never use UV filters.
9. Never ask why Gary does what he does. (do your own research)
10. If you don't go, you can't be there.
11. Always have your camera at the ready. (see rule 19, Bob's postulate)
12. If you see something interesting, take a photograph of it.
13. Never talk about the picture unless you can show us the picture.
14. A picture isn't worth a thousand words. It's worth the comments it receives.
15. Share your photographs with others. Any picture that isn't seen is worthless.
16. Edit your own photos.
17. Don't buy a junk tripod.
18. Never take a photograph of somebody with their mouth full of food.
19. Walk softly and always carry a camera. (Bob's postulate)
20. Always wear good sturdy hiking shoes in the mountains. Wearing good mountain boots kept me from breaking an ankle, again.
21. Don't carry any more equipment than you'll need. I took 2 bodies and 3 lenses with me last trip. I was thankful that at the end of the day, my pack wasn't tearing my back up.
22. Don't forget to stay hydrated. Always bring water with you on a day outing. At high elevations, you'll get dehydrated quicker than you can fall down a hillside.
23. Memory cards fail. Always check your files when you have the time. Always bring spare memory cards with you. The last thing you need is to find out you've lost 100 photos to a bad memory card you didn't catch and replace.
24. Put a small first-aid kit in your bag. I guarantee you sooner or later, there will be blood.
25. Sunscreen. Did someone say sunscreen?
26. Don't set drinks next to your camera.
27. Bob's rule of gravity. When you set your camera down set your camera on the ground. It isn't the fall that does the damage, it's that sudden stop at the end.