I suppose there are as many "debugging practices" as there are "campers who use them"... I'd imagine everything from sprinkling Ajax around the picnic table to sprinkling old, used cat litter to ward off snakes and mice....
All that said, here's what we do if we are in a campground with water connections. Spectracide sells a "garden hose end lawn insect spray" that you simply attach to a hose and spray the ground around the trailer. It lasts until the next rain, then you'd need to respray the site. We use it at home (we live in the woods next to a lake) and we sit on the back deck without bugs all summer long. I take a "bottle" with us when we travel.
If, on the other hand, we are camping where there is not a water connection, I have an old "propane fired fogger" that I use to "smoke the bugs out". It's not as effective as the Spectracide, and needs to be reapplied several times through the evening, but it does keep the bugs at bay well enough that you can sit by the campfire without putting "bug spray on you or your clothing"...
Both are available at Lowe's, Home Depot and most hardware stores.