If you are not actually on a 'campsite', for example when out hiking in remote regions, then care should be taken when deciding the actual location of your campsite (before we come to layout).
If you are on high, exposed ground go down to find a sheltered spot. Similarly though, when on low, wet ground seek higher shelter. Look for somewhere sheltered from the wind, on rising ground that has no risk of flooding, and no risk of rockfalls/avalanches.

Remember that hot air rises, cold air sinks. Valley bottoms often contain pockets of colder air, and can be areas for frost and damp mist.

Ideally you should be near a good, clean water supply (although not too close. Pitching camp near the water you will be invaded by insects!). On river banks look for the high water mark, and be wary of flash floods in mountain ranges where streams can suddenly turn into 5m of water with almost no warning!

Choose ground that is reasonably flat and free of rocks and roots.

Don't forget to check above your head too. Look for dead wood in trees that could fall, bee's and hornet's nests are not very nice neighbours either. Keep away from solitary trees as they attract lightning. In forested areas keep to the edges of the forest. Take careful note of any tracks, including those made by game. You will not want unwelcome animal visitors in the night.
Do NOT camp at the following;
  • Hilltops exposed to wind (move down and look for shelter on the leeside)
  • Valley bottoms and deep hollows. They could be damp and more liable to frost
  • Hillside terraces where the ground holds moisture
  • Spurs which lead down to water (often routes to animals watering holes)