[It may help to read this post first.]
1. Immediately switch to hybrid or electric car technology.
2. Don't eat all the trees.
3. Consider building footbridges over sensitive riparian lands and streams to prevent excessive trammeling of plants and amphibious species.
4. Meat-eaters: Can what's left of that carcass be composted? Chances are good that it can.
5. Whenever possible, carpool on your ancestral migrations.
6. Plan ahead: Don't make five foraging trips every day; try foraging at all five locations in just one trip.
7. Leave at least 1.5 inches of grass when grazing to prevent erosion.
8. Install highly-efficient filtration systems in the rectums of the gassier species.
9. Take only pictures, leave only massive footprints.