Are you an avid camper? What's your style? Do you grab the family, hop in an RV and drive to the closest local campground? Do you take a tent out for the weekend? Maybe you go up into the forest with a tarp and a sleeping bag. Whatever the case may be, you should always be conscious of the impact that your camping has on the environment as well as your fellow campers.
What exactly do I mean by "the impact" that you have? Well, first we'll break it down to the two types that you can have: good and bad. Simple right?
Have you ever gone out to enjoy a nice relaxing day of fishing only to find your favorite area strewn with trash and debris? Or perhaps some nearby children were throwing the large rocks from the bank into the water? I think I can say that we all have.
It may not seem fair that you didn't make the mess, but in many cases, cleaning up just that little bit may end up being left to you. Not only will cleaning up that little bit of trash make the area look more presentable and be a better spot for you to relax, but you've also made the area better for other people AND for the wildlife and in general the land and water around you. It may be something as simple as picking up a discarded jug of laundry detergent that someone left behind, or it may be as difficult as removing a nasty, tangled clump of monofilament from a tree, but in all cases you have improved everyone else's experience in the area including your own.
Leaving trash all about isn't the only sort of impact that you can have that will negatively effect someone's experience. For instance, if you're at a campground, even in the middle of the day, it is probably frowned upon to play loud music, light off fireworks, or burn smelly or unsafe trash in your fire pit. In addition to that, I have seen a lot of people pick up interesting looking rocks or pick a pretty wildflower. Those people probably don't realize that because they have picked up that rock, or picked that wildflower, that all of the other people who would have encountered it will now miss out on it. In any case, before you leave an area, make sure that you leave it in the way you'd like to encounter it, even if you didn't leave the mess.
In all cases, be courteous to those around you and remember that people are usually at the campgrounds to relax and to be a little bit closer to nature, so leave nothing but footprints and take nothing but photographs.