Mental preparation
How does one practice this shot in the best possible manner?
My recommendation is:
The absolutly best way to train this is on the course or in competing form around the pitchinggreen when one is more fixated on results instead of technique.

What is a pitch?
1. A pitch is a shot with a wedge or sandwedge within 100yards of the hole.
2. The distance where 70% of all shots are during a lap on the course.
3. The shot that usually decides wether you make birdies or saving a par during a lap on the course.


Basics:
Naturally one must have a basis that's simplae and easy to repeat. When one plays on the course one should only think about the target and not the technique. The technique you only practice during trainingdays. When you have a technique that you're satisfied with you just get a stance and start pitching for the hole without thoughts about the technique.

The basis of a pitch is built on straight arms that oscillate freely towards the target. Why I want you to go for an leftarm that's as straight as possible is that the distance from your center on your chest to the club or grip will always be the same. This gives us a constant, clean hit and better results. Combining this with a touch in the hands and a low swing one gets the results one wants. To discuss the technique in more detail I'd like to divide it into short and long pitches. Short pitches are shot with a swing up to 50% of a full swing. and long pitches are more like a full swing with a wedge.


Pitch yourself to a good game!
Before we go into the technique you must understand that pitching and shortgame are mostly built on the mental attitude and not touch or technique. One has to believe that one is going to make a "up & down" (2 shot maximum). If one does not then one must create a routine where one builds a confidence to be able to make every pitch.

That which seperates the pros from the amatures is not that the pros are that much better golfer, they just miss better. Any amature kan hit a supershot now and then but miss even more. Trying to hit the hole while pitching usually puts you within a few yards from the hole even if you miss. But if one is aiming for just the green and miss by 2 yards you might end up in a bunker or a water hazard, or even lose the ball.

When asked what he thinks about while playing basketball Michael Jordan just said that he looks at the basket and shoots. Sounds simple enough, right? But it's not supposed to be any harder than that. You have to practice until you get a feel with only the target in your thoughts, not the technique. When asked what makes him a dominant player on the tour Davis Love answered:
"A clearly better game around the greens."
He tried making all shots instead of just placing the ball close to the hole. The result was that he started pitching and chipping in the hole more and more often, and when he missed the ball ended up better closer to the hole. The average golfer works the other way around and only sees trouble which can easily result in 3, 4 or even as many as 5 extra strokes before making the hole.

You decide what your goals are!