ORIGINAL: adams
If you're hunting crowded public land it's best to get in early. if you're walking in and see lights flashing at you from high in a tree it's best to move on as the spot is occupied. This is not required but is good etiquette.
I totally forgot about this one. I cannot tell you how many times hunters have done this when I hunt public land. Please get in the woods early, be quiet when walking to your stand and if you see a light flashing at you, respect the fact that the other hunter is there and find another spot.