It's important to find a good tent site, which is why an early start is important, so you have plenty of time to do so.
A good tent site is level, dry, with some shelter from the winds. Trees are a great natural windbreak. A canopy of branches also provides a warmer campsite than one in open ground, in a meadow.
Valley bottoms are usually colder than side slopes, because of cold air drainage from high to low ground during the night.
Setting up a tent is always the first thing I do when I get to camp. I find security in having a shelter up to escape wind and rain. Tossing my gear inside ensures it stays dry.
One of the main common sense rules of the backcountry is to keep your sleeping bag dry. You can survive almost anything if you have a warm and dry sleeping bag. The primary way of keeping it dry is to have a solid and sturdy tent over it.
As added protection though I always have an outer waterproof shell around my sleeping bag. This is especially important if you sleep with dogs in the tent, like I do. They can be sopping wet and my sleeping bag stays dry.
I always like to have a good view near my tent site, and often find myself climbing up to ridgetops to find a place to set up camp.
Ridge and hill tops usually have level ground near their summit. If you can't make it to the top, look for large rock outcroppings part way up. The soil usually collects on the upward side of the outcroppings, where you can find level ground.
Last weekend I had a choice of setting up my camp down in level ground of an aspen and lodgepole forest. Instead I chose the top of a ridge, where I could see snowypeaks from the southwest to the northwest. Back in the east I had a great view of the moon coming up right after dark.
The wind blew all night, but my tent stood steady, even in some gale force winds. That sunset and moonrise, and the sunrise the next morning were more than worth the wind. Check out more photos of my backpack trip here.