Take nothing but pictures, leave nothing but footprints: If Bigfoot can do it, so can you!
Travel and camp on durable surfaces. Stay on trail as much as possible; as much as you’re going to want to, do not cut switchbacks. Camp in designated sites whenever possible to minimize your environmental impact. If you stealth camp, don’t alter the area to “make room” to set up camp. Leave those flowers/ fungi/ shrubs/ small trees alone.
Dispose of waste properly. Pack out all trash and food waste, including garbage that someone else left behind. Packing out human waste is the preferred method to LNT Purists, but if that’s a little too extreme for you, be sure to burry human waste at least 6 inches deep and 200 meters (or more) away from water sources.
Don’t bathe in water sources that humans drink from. No one wants to drink the DEET or sweat that washes off your body. Snag some extra water and pack it to camp. Sponge bathe 200 meters away from designated camp sites and water sources.
Leave what you find. (Unless it’s trash, of course) Don’t take flowers, rocks, or other sensitive natural resources. Don’t pull rocks out of the ground to make a flat camping surface; it accelerates erosion, and definitely do not roll rocks down steep embankments- you could cause some serious dome-damage to humans hiking below you. Don’t carve your name in trees, shelters, or soft stone. Don’t steal trail maintenace workers’ tools or supplies (they know who you are, and they know how to make booby-traps). Don’t steal other hikers gear (they will hunt you down, and they will probably kill you).
Minimize campfire impact. Try and build campfires in established campfire rings, using only downed, dead wood. Be sure the fire is completely extinguished before you go to sleep or depart the site by pouring water on the embers until the steam ceases to rise. Once the white ashes are cool to the back of your hand, mix in the soil and spread around the area. Be sure to stay up to date on local fire regulations and fire ban notices for each area you pass through.
Respect the wildlife. (Which may, or may not include the person who took one too many sips of whiskey) Store food (or whiskey) properly to avoid attracting bears and rodents (or guy looking for whiskey). Keep pets on leashes. Do not kidnap wildlife to bring home to raise as your pseudo child.
Be considerate of other visitors. Minimize noise and intrusive behavior (I’m looking at you, drunk whiskey person). Avoid loud karaoke camp parties, and throwing knives/ ninja stars at trees (slightly dangerous for nearby hikers, also damages trees- double offence… a big no-no).