What is the proper way to trot?

when the outside leg goes forward you rise and when it goes back you sit. this is called posting on the right diagonal which needs to be switched when you switch directions.

okay when you post you swing your hips forward into your hand which should be up and not on the horses withers swing your hips forward without tucking your but under so you can drive the horse forward and eventually start collection.

http://www.youtube.com/watch?v=yb5HorXDsjk don't pay attention to her diagonal she is on the wrong on most of the time, but look how this rider swings forward instead of up.

It's likely that the first one was teaching you hunt seat and the second was teaching you dressage.

In dressage, I see a lot of people riding behind the motion (straight up and down at the trot), in a driving seat.

In hunt seat, you generally move with the motion (leaning forward slightly, which causes you to post up and forward), except when pushing a lazy horse forwards or restraining a fast horse.

If not, then go back to the first riding instructor.

I am guessing you are riding in a riding arena, right? Well when you trot, you follow the horses movement; when the horses front leg steps down (while trotting;; the leg that is not facing the fence), then you sit down. When that leg goes up, you go up and follow that rhythm. Sit straight up, follow the movement and don't sit too forward or back too far. When you sit the trot, sit deep into your seat.

Many trainers teach "new" riders to post straight up and down, because I believe it is just easier for the new rider to learn at that point. When you become a more experienced rider, the correct motion is actually slightly forward (meaning you move your belly button forward,not your upper body). It is actually a very natural motion and when trotting properly the horse's motion actually propels you slightly forward.

when you first learn how to post a trot trainers often don't really care about your position as long as you get the concept of the rhythm (1 2 1 2...)

but you should think of it more as your belly button or hips are going towards the ears of your horse each time you go up, it kind of comes naturally because posting straight up is more work.

Up/Forward is more correct but the other instructor may have been trying to correct your tendency to lean too far forward.

i've found over the years of rideing horses is that when ur horse is troting u post w/the rythem of ur horses trot once u find the rythem the rest will fall into place

It is forward and up, using your hips to drive the horse forward.

rise and trot rise and trot.........................ect :)