Resist the urge to pioneer a new road or trail, or to cut across a switchback. Stick to routes open for use. Stay away from wild animals rearing their young - or suffering from food shortage. Stress can rob scarce energy reserves. Obey gate closures and regulatory signs.
Vandalism costs tax dollars.
Take out what you brought in. Encourage others to keep a clean camp by doing more than your share to rid the back country of litter. Stay out of designated Wilderness. They're closed to all vehicles including mountain bikes. Know where the boundaries are.