Leave No Trace
Leave No Trace - use this link to learn about the 7 principles. This is not optional. The beauty and longevity of our amazing outdoor areas depend on taking this seriously. I have seen too many wonderful places marred by carelessness and laziness. Leaving no trace can be particularly challenging for large groups and you may need to take special measures to deal with that. While it can seem a bit annoying at first, over time, it is fun to see just how well you can leave no trace. It probably sounds cheesy, but I like to think about leave no trace as if I were an outlaw with a big posse trying to find me. I try to take every precaution so that nobody can tell I was there - that I walked there or ate there or slept there or went potty there. Complying with the 7 principles forces us to think outside of ourselves. We see the wilderness not as our property where we can do whatever we want, but as a shared resource temporarily entrusted to us. We wouldn't borrow our friend's phone and return it a few days later scratched up or cracked, smudged, and with some apps deleted and lame ones installed. When we take a step away in the wilderness, we want it to look as good or better than how we found it. Please pay particular attention to toilet paper. There is nothing more disgusting than walking in the woods and stumbling onto someone's TP scattered all over. Animals get into TP and will tear it up and spread it around. Bury it deep (6-8 inches) even if you just went pee (females), unless regulations require that it and waste be packed out (some areas do). Assuming it doesn't have to be packed out, taking a stick and making poo stew (sorry, but it is best description) is even better. Stir dirt, poo, pee, and TP together - it all disintegrates faster (animals can't drag it around because it is all super small/shredded already), and the hiker (which could be you) that comes through tomorrow won't have to look at a nasty mess. Be sure to bury the stick in the stew too. If you prefer, you can bring a small, lightweight shovel to dig your hole.
Trash - By carefully planning, you can minimize the amount of trash you will have. I always take a 1-gallon freezer-weight Ziploc bag on my hikes and that is my trash bag, not some great big trash bag. I roll things up, smash them down, and put it all in that 1-gallon Ziploc bag. Think through what you plan to bring to be sure that your trash will be neat, tidy, and compact. Keep the outside of your trash bag clean because it will go in same bear bag your food does at night. Proper planning can make dealing with trash super easy. Carelessness and poor planning will mean you are bumping down the trail with a stinky bag of nastiness swinging on your pack.
Keeping your hands clean - Backpacking is dirty business sometimes. You hands will get dirty and that is OK. That said, be sure to wash your hands before eating and especially after going potty. We don't use soap in streams or lakes because it is bad for the plants and animals. If you use soap, you will need to dig a hole, wash with soap into that hole, and do that 200 feet away from water. Not fun or easy. I typically wash my hands with regular old water and then apply a good dose of hand sanitizer. I strongly encourage you to bring hand sanitizer too. I also bring one anti-bacterial wet wipe per night. I use it on my hands before taking my contacts out and then wipe accumulated sweat, sunscreen, and bug repellent off my face and neck. You are more likely to get sick from poor hand cleaning practices than from anything else while backpacking. If your friend asks you for some of your snacks, shake them out of the bag onto their hand instead of having them rummage their hand around in your food.
Example - This microadventure is from Hell's Canyon (Idaho side). This is a very deep canyon that separates Idaho from Oregon. During the summer, this area can see a lot of people passing through it. The majority come in on jet boats up the river and stop at an old ranch now converted to a rustic museum on the river. I backpacked into this area in November a few years ago. It was great to see how clean it was and we were very careful to make sure nobody would know they had even been there.