1. Plan your route. Have a few ideas of where you would like to camp in advance and give yourself time to arrive there before dark. If you find the perfect spot on the way you can of course stop there instead.
2. Weather: Check the forecast and the sky. Look for a pitch which will give you the most shelter from heavy rain or strong winds. Consider the lee of a hill or behind a wood or wall if possible. Pitch your tent end on to the wind, it will be much less noisy and will give you a sheltered area in the porch.
If you are out in midge country, look for a pitch which isn’t too close to standing water and does have a breeze and as this might help keep the beasties at bay.
3. Beware of falling objects. Don't pitch somewhere too high or exposed, instead opt for somewhere that has some natural shelter from the wind such as boulders or trees but avoid seeking shelter from the wind under a cliff as there is always the hazard of rock falls. In forests look up to see look and see if f there are any dead branches above a prospective site or dead trees that might fall.
If the weather is set fair, don’t forget to look for a pitch with a view. If the sky is clear, take time to look at the stars, with less light pollution you will see much more than usual.
Examine the ground, look for a reasonably flat area with no rocks or holes. Try to find a pitch which is slightly raised as it will be drier and less likely to flood in heavy rain. If you can’t find a completely flat spot, pitch so your head will be uphill.
A spot near running water is best. Consider where you will take your water from and where you will dispose of dirty water. Camping next to a trickling stream may seem idyllic until it becomes a raging torrent. Be aware of the weather and potential for flooding. With this in mind, keep your campsite close, but not too close, to a water source.
Plan where you will toilet, ensuring that you are well away from water supplies. Dispose of waste responsibly.
Be organised. Once the tent is pitched, lay out your gear sensibly so you can find things like headtorches, food etc in a hurry.
Keep things clean. Try not to bring muddy boots or wet waterproofs into the inner tent as this will get your other gear wet and dirty. The porch or a dry bag are great for storing this stuff.
Leave it spotless. In the morning, ensure that you have everything packed, check the site and tidy any leftovers, moved stones etc. You should take away nothing but memories and photographs and leave behind nothing other than a patch of flattened grass.