Several things to do about insects:

Put your tent where it will get some full sun during the day when you probably won't be in it anyway. A good breeze helps too, even if you have to give up some shade to get it.

Before you pitch your tent, it's a good idea to rake/sweep the spot where you are going to put it. This gets rid of the leaf/twig & other trash where the little critters hide.

I know it's tough to do, but avoid keeping huge mounds of assorted junk in the tent. If you really want to keep a clean tent, you should be able to see almost all of the floor. Pile things on folding chairs or stools, to keep them OFF the floor, if necessary.

Ventilate the tent as much as possible during the mid-day, when flying insects are least active. The creepy-crawly ones generally don't like fresh air. Let some sun in, if you can.

Close the tent up as tightly as possible BEFORE the bloodsuckers start flying in the evening.

Most of the really objectionable creepy's don't like a lot of activity around, so plan for all night action in the tent (be careful about accepting volunteers - some of them can be worse than insects.)

Don't eat bananas. (Persuading a friend that bananas will keep the mosquitos off really works. It will keep the mosquitos off YOU, if someone else nearby eats them.)

And most of the above good advice.

JohnInKansas - home of the Dobson Fly - really ugly but harmless - my hero(namesake?)