If you want to have a good night's rest you have to make sure that the site you choose  is conducive to sleep. The campsite should ideally be flat and provide sufficient protection from the elements.

One of the worst place to sleep is on a slope. If the slope is sideways you'll wake up tired and aching because whether consciously or not, you are battling with gravity.

If the slope is from head to feet going upwards, blood rushes down to your head and you might not be able to sleep at all even if the incline is gentle.

If you can't avoid sleeping on a slope, you can at least make the night bearable by keeping your feet downhill. However, in the morning, you might find yourself a few feet from where you originally laid down on your camping mattress and pillow.

Make sure there's no fire burning downhill from where you sleep or you'll wake up with something more than mildly aching leg muscles.

Bumps, rocks and other things that can poke you when you sleep should be removed as best as possible if present where you intend to sleep. The thinner the sleeping pad that you're using, the more attention is needed in clearing the area.

If you're using an air mattress or a self-inflating pad make sure you clear anything sharp that could puncture your pad.

You can use the surrounding material to make your bed in the outdoors a bit more comfortable by giving it some more cushioning. Grass is a poor choice for a bedsite unless when it is very long. Sand is one of the best in terms of cushioning but nothing beats a carpet of pine needles in terms of warmth and comfort.

In fair weather, a level ground is the most important feature of a good bedsite. When the wind is strong and cold, shelter from the wind becomes much more important if you want a good night's sleep.

Finding a natural shelter from the wind is essential on a cold, windy day unless you can erect a tent in such a condition. Any obstruction like trees, large rocks or bushes can do wonders in keeping away the full force of the wind.

You can also seek shelter in the troughs of shallow gullies, behind low walls or under a rock ledge. A cave provides the best shelter from the wind but most people would rather not go inside a deep cave unless necessary.

Rock ledges are great shelter from rain and yet again caves are even better. You need to be wary when taking shelter in shallow caves in a thunderstorm because they're prone to lightning strikes.

If you have a tent, it's not really necessary to find a rain shelter but it doesn't hurt to choose a sheltered site anyway.

Small openings in the forests, brushy hollows or encircling rocks are great shelter from the snow especially when the wind is driving it. Overhanging cliffs might be safe if it overhangs enough or else there's a risk of icicles or rocks falling on you.

You should avoid spots where it is windy and where the snow is deposited or blown away which includes steep treeless slopes or gullies. For your own safety, avoid places where there is a risk of avalanche.

A good campsite may also depend on personal preferences among other things but never underestimate the importance of being close to a source of water.  It's nice to have easy access to a source of water but you don't want to be too close for fear of flooding and the presence of mosquitoes and other bugs in warmer weather.

The availability of firewood for building campfires can also make life easier. A pleasing surrounding can make the experience better. Depending on the season and situation you also might want to consider positioning yourself to face or avoid the morning sunshine.