Teeing up with irons...

What ball position should I use for midrange irons and short irons...? I can't irons off the tee easily, but I do ocassionally catch the ball clean sometimes. I am very inconsistent though.

I like to tee them up fairly high to get a high ball, so I'll generally use 1 club longer than if it was off the fairway, and belt them as hard as I can so they get a longer air. I'll play the ball from the middle of my stance.

Unless you are trying something special (like trying to deaden the hit or something) you should tee the ball so that the ball is "just" off the ground.
Literally the width of a tee of the ground.
Its tempting to tee it higher and play it more forward, especially with the lower irons but I think its unnatural and you are only going to get a max of 18 of them a round...

I use tee height depending on the distance required.
I tee up the ball about 1 cm high to use 3i for 185y par-3 and for 215y par-3 the tee is almost fully in the ground. My ball position for teed up ball is just about an inch forward of the center. Well! one can argue my club selection for the above but this has been giving me the best results, as my control of woods is poor.