Choose the “high/level ground”

This will keep you from getting wet and also it will keep you from rolling out of your sleeping bag or mattress all night. If you ever set up a tent in the lowest area of the site you better hope it doesn't rain because it will run right in your door.

Check for a water source

People need water if you didn't pack enough water for your trip you better camp near some or you will be getting a lot of exercise walking back and forth to your water supply. Of course if you are planning on pulling your water from a lake or stream you better bring some form of water purification device or pills.

Find a good area to place your stove or to build your fire.

Never cook in your tent. This may seem obvious but people light their tents on fire all the time their stove or grill. Also avoid anything flammable you don't want to burn down the forest.

Bring trash bags.

You always want to leave your site as you found it or better. Litter is never an improvement to a campsite. They are also great as an impromptu poncho in the case of a quick storm. Someone you camp with will leave their water resistant jacket at home.

Choose a campsite with shade.

Unless you want to site in a chair 100 yards