Practice no trace camping. This means that you leave the area you visit just the way you found it or even cleaner.
Use existing camp sites, trails and portages. This will minimize the damage to vegetation and wildlife habitat.
Use a camp stove if possible as these have a minimal impact and have a low risk of causing a forest fire. If you do have to make a camp fire, use only dead wood as fuel. Do not cut live trees for firewood (green/live wood doesn't burn well, anyway). When looking for fire wood, avoid trampling or damaging other plants.
If you are on a small island, gather your firewood off the island, saving it from being trampled by repeated scavenging. Keep your fire small and use existing fire pits.
If you are using/creating a new camp site, remove all trace of your visit before you leave, including the fire pit.
Completely extinguish your fire before you leave. Keep soaking the fire with water and stirring the ashes & coals to ensure all are cold. If you can put your hand into the ashes/coals, it is out.
Avoid digging drainage ditches around your tent or camp. If you absolutely have to, make sure that they are smoothed over before you leave the campsite.
The placement of your tent should take into account the drainage around it.
Do not build a new fire pit - use the existing one.
Do not cut live trees and shrubs for tent poles or to make shelters.
Do not use soap or detergents near a body of water. Even biodegradable soaps pollute the water and leave an unsightly trace.
Do not wash dishes directly in a lake or river. When washing dishes, washing your body, brushing your teeth, or shaving, use a small water container and disperse it at least 15 metres (50 feet) away from any existing water sources and the camp site. Try to avoid damaging the ground cover when pouring out water.
Use park latrines and washrooms where possible.
Look for "Thunderboxes" at the camp site.
If none are available, dispose of human waste at least 20 metres (60 feet) away from water sources and the camp site. Dig a hole at least 15 cm (6 inches) square and deep for human excrement. Cover it over after use.
Bury your toilet paper or burn it.
Eat or burn left over food, or carry it out with you. Do not bury it near the camp site as this will attract unwelcome wildlife to the site and they will make life unpleasant for future users.
If you bring it in, take it out with you.
Leave nothing behind. If you find garbage from previous inconsiderate campers, if possible, burn it or carry it out.
Remove all non-combustible items such as tin cans, foil wrappers, glass, and plastics, and carry them out with you. Do not burn plastic items.
Many parks have tightened regulations and restricted access because inconsiderate campers have left behind garbage or damaged the bush around camp sites.
Ideally, the only thing you should take out of the bush are memories and the only thing that you should leave are footprints.