When in Italy I came across an old foe, the Squat Toilet. Here is an article that better elaborates just exactly how to use one of these fine contraptions.
Rule One: Exhaust all other possibilities.
If you are truly in need and condemned to use the squat toilet, comfort yourself with the knowledge that you are several thousand miles from friends and family. No one has to know.
Proceed as follows:
Most stalls do not have toilet paper. This is the best time to realize this. Either take paper from the general dispenser in the bathroom area or preferably bring your own as it will be made of tissue and not plywood carpaccio.
Approach the squat toilet apprehensively and make sure it's not covered in stool. If it is covered in stool, choose another stall. If another stall is not available, accept the cards that have been dealt you. This is a good time to come up with a title for your experience such as My Great B.M. Adventure or Disgusticon One.
Close the door to the stall, knowing full well the handle has more germs on it than the entire population of Botswana.
Place your feet on the appropriate foot grids, assuming they are not covered in stool. If they are covered in stool, place your feet on the least fouled space you can find, being careful to maintain balance.
Unfasten and drop your trousers and underpants, making sure that they do not make contact with the urine and stool covered surface area.
Grimace and ask yourself if a country with such a toilet can or should ever be a superpower.
Assume a squatting position like a competitive ski jumper. Stick your ass out like a whore in a 50 Cent video. This is a good time to pretend you're not a miserable tourist with your pants around your ankles, squatting over a barbaric poo hole.
Use your right hand to prevent the soiling of your trousers and underpants by holding them off the ground and pushing them forward, away from any Danger Zone. This is perhaps the best time ever to be a kilt-wearing Scotsman.
In your left hand should be the assortment of paper/wipes/anti-bacterial sheets you intend to use after you are finished with your production.
You would think you would want your left hand to brace your squatting self against the stall wall. However, the stall wall is covered in nose nuggets and as such is not touchable. At any rate, if you have a penis you will need your left hand for guidance anyway.
For the penised: Use your left hand to aim it away from your trousers and underpants. Point it backwards between your legs - as if it were a rocket engine designed to propel you far away from this alien hellhole. At the same time be sure not to drop any of the objects in your left hand as they will be rendered horribly irretrievable should you do so.
If you do not have a penis, use the left arm to balance yourself - waving it around wildly rather than touching the snot covered stall wall or filthy support bars (if any).
If you are able to maintain balance for several seconds, you are ready to begin bowel evacuation. At this point the bulk of your focus should be towards the quick evacuation of your bowels without soiling your clothing, missing your mark or - God forbid - losing your balance and falling.
For aiming purposes keep your head tucked between your legs - like a bombardier on a very unpleasant mission assigned by General Squalor.
If your aim is true you will have the pleasure of watching poo (yours) drop down a deep, dark hole to a resounding ploot. If it's not true, you will have the pleasure of watching poo (yours) come to rest on the floor between your legs.
After you have completed your bowel evacuation, DO NOT STAND UP. Remain squatting and miserable.
Continue using your right hand to prevent contact of your trousers/underpants with urine/stool. Place your tissues and wipes in your left hand on top of your underwear/trousers and select the items you need for wiping.
Wipe and curse culture simultaneously, all the while maintaining the squatting position.
Do not drop soiled tissues. That would be too easy. Sadly, the 16th century plumbing can only handle poo. Soiled tissues are to be placed in the bin behind you. Without leaving the squat position, twist your body in order to see the bin and make a good throw. Don't worry if you miss, as it's obvious from the poo-sheet pile on the floor that even the squat-tastic natives are no Michael Jordans.
Once sufficiently wiped, humiliated and traumatized, you may stand and re-underpant and re-trouser yourself. This is a good time to reflect on your life and also a good time to try blacking out these last ten minutes - like a freshly-sodomized felon might do.
The filth-covered flush button is behind you and may or may not work.
Open the door to the stall, again knowing the handle has more germs on it than a decade of scrapings from Paris Hilton's tongue.
Exit the stall and never, ever, ever get yourself into a situation where you have to do that again. But first, wash your hands until they bleed.
Leaving Innsbruck
Stopped for gas 
