Remember to give a quick look around before leaving your break spot, especially if you took your pack off and opened it. You don't want to go back for something left behind, and you probably wouldn't find it anyway. This is especially true at night. Always carry an extra compass. It is one of your most valuable essentials.
Whistles also are necessary, cheap and light.
Look back periodically especially when you are traveling off trail. It will help familiarize you to the terrain in all directions and keep you on track if you come back the same way. Dryer lint makes great fire tinder. A handful stuffed into a film canister weighs nothing. Keep a list of items that you want to take always handy so that before you drive away you can quickly go through it and make sure you have everything.