This is asked often!
If using a privy, it’s pretty much just like at home, just no flushing. Don’t count on there being TP, always have a personal stash. Check for spiders and mice, and leave the door open if possible!
Wearing a skirt (not skort) with leggings allows freedom of pulling underclothes out of the way while the skirt keeps the buns covered. This is really great in winter when brushy cover is at a minimum.
If having to use nature to wipe, look for wide deciduous tree leaves. In winter, grass or snow will work. Avoid using plants along the trail or vines, many can cause irritation, not just poison oak/ivy.
The basic gist is the same and each device has it’s own little perks and drawbacks. No more pulling down pants. Or taking off packs or doing much more than get the required 200 feet from the trail and water and weeeeee. Holding it firmly against the body will create a seal and the pee won’t go out the end and might backflow over the top. A good option is to get the funnel firmly in place, start it up and then tip it down a tiny bit to release the vacuum and-no problems! Try at home a few times so confidence is high. Advantages include using less toilet paper. The funnel sheds water, just have to blot it and pop it back in the bag. A rinse at the end of the day and it’s good to go. After many different device tries, I suggest the pStyle because it does not create a vacuum, it’s rigid enough to use one handed and is soft enough to use as a squeegie, so a quick blot with TP or a pee rag and you are all set.
In a hurry or helping a younger kid with no aim? Poop first and then dig the hole and roll it in with a stick. Use the ‘balance on a log’ method from above or face a small tree, grab it for balance and squat or free squat no-hands, though that’s hard core!
Keep poop trash totally separate from food trash. Some people use a little bleach in the used TP bag, or borax or even baking soda. A tablespoon or so is enough. Wrap the bigger TP bag in duct tape or use a black odor-free bag like for used coffee grounds to really ID that it’s non-food. It will still need to go in with the food and toiletries if you bear bag.
Encourage youngsters to pee and even poop in the yard before heading out on a trip that they will have to go in the woods. Some kids could not care less and some panic or are embarrassed and try to hold it until back in civilization. It’s scary having the most private bits out there for any squirrel to see!
To keep UTI’s at bay, keep that system flushed. Drink plenty of water, don’t hold it (a wide mouth jar in the tent at night can be a big help in wet or cold weather) and keep everything as clean and dry as possible. Clean hands well after using the bathroom (poop to mouth is the leading cause of backcountry diarrhea) and at least once a day, use wipes or turn a water bottle into a mini bidet and squirt clean water on the nether regions to keep things hygienic. Wearing wool panties instead of synthetic or cotton will keep the swamp effect minimal. Bamboo is a good alternative and can be far less pricey than wool!