Witchy Woman

If you're in town, answering nature's call isn't that big of a deal.  But say you're in the back end of 40 acres and have to hold your position and bladder, what do you do?  A couple of people (of both genders) I know hold it all day long, which is unhealthy and not an option for some.  Luckily for you, I spent a couple years on trail crew and experienced in no-trace camping where the closest flush-toilet was eight hours away.  (We would even swap stories around the campfire of what was the best natural alternative to toilet paper, and the most comfortable positions to assume).  With a couple supplies, and some knowledge, you can mark your territory with ease.
1.  Hand sanitizer
     While on-site, I carry this on me at all times.  The 2 oz. bottle is discreet, and can be easily palmed in order to prevent breaking character.  (Bonus: I get the larger sizes because they're cheaper, and refill my little bottle).
2.  Tissues
    Even if you don't plan on needing to find a bush, sometimes the latrines are out of toilet paper or someone is simply having an allergy attack.  Keep a handful in a pouch or a closeable pocket to prevent wetting or soiling before you intend to wet or soil them.
Once you have an attempt at the trappings of civilization, familiarize yourself with poison oak/ivy/sumac (depending on your region) and stinging nettle.  Even if you do not react to urushiol, you and your gear can spread the oil to others, which can be dangerous.  For example, every time that I'm exposed to it, I end up on steroids because my eyes and airways swell shut.  So be careful.
Now to pick a tree or bush free of poison ivy/oak/sumac, stinging nettle, and brambles that is a sensible distance away from bodies of water and the trail.  (Nobody wants to step in your mess, nor have the swimming hole contaminated).  With a sturdy stick, dig a "cathole" deep enough to suit your needs.  If it's #1, only a few inches is necessary.  For #2, six inches is ideal.  Set your stick aside as you will use it to push the soil back over your nightsoil.
Before you can assume the position, ensure that all your pouches, weapons, clothing, and other dangly bits are tucked away out of the line of fire.  Since both of my characters wear skirts/robes, I pull the bottommost hem (usually my chemise) up around my waist and draw the excess to the front.  In this process my overskirt, pouches, and weapons are safely enveloped in my skirts.  When it comes to pants you might be better off just removing your belt.
Get comfortable.  I typically just squat in a wide stance, ensuring that the topography won't funnel anything back onto my shoes.  The bulk of my skirts are sandwiched between my torso and my thighs.  If it's a big job, then you may wish to grab the backs of your ankles or, if the land slopes steeply enough, you can put your hands uphill behind you to support yourself.
When your deposit's been made, use as little tissue possible.  (Animals can dig it up and eat it, making them sick).  If you're feeling particularly adventurous and recognize poison ivy/oak/sumac, experiment with plants.  My days on trail crew gave me an appreciation for young sage leaves, soft and sweet-smelling.  A second close is pine needles, taking care to use them with the grain, not against.  If you're careful, rounded river rocks work well for #2.  Just do not use sandstone, as one of my old crewmates learned the hard way.
Sort out your clothing and squirt some hand sanitizer.  Take the stick you set aside before and use it to scrape the displaced earth back into the hole.  If you were unable to dig very deep, place a big rock over it.
This sounds like a lot of work, but it's mostly thinking about what you're doing when it comes to both yourself and your surroundings.  But if you happen to use a she-wee, let me know what you think.