Your windup is the big difference in throwing a long or a short pass. I guess that's the big difference in throwing a fast ball or a curve, for that matter. At left, on the far side, I bend my knees just a trifle for a short pass. If it's going long, I crouch more, but the pass is thrown with the same motion; you just get more body behind it with the deeper crouch. The grip is the same and you still step toward the target with your left foot; just remember to drop into a deeper crouch so that you get more weight and movement behind the ball before you release it. Accuracy on a long pass, as I said, depends on the depth perception the good Lord gave you, plus practice.
Your left foot, I guess, aims your pass (see below). At least, the left foot should be planted in the direction in which you intend to throw the ball. You can look away to try to draw the defense in the wrong direction, but when you throw the ball you have to step along the line of flight with your left foot. There are a few passers in the league who face in the direction they're going to throw, but they're what I call belly-button passers. You get more power and more accuracy if you pass the way you bat or put the shot—with the left side and the left foot pointing the direction of the missile in question. That is, after all, the natural way to throw a ball.
Your grip—the two middle fingers together is my own peculiarity. Usually passers have them spread. The tip of my little finger is on the laces, I hold the ball just back of the center.
Your hand's size determines how far back you hold the ball. Not everyone puts his little finger on the laces. Some put the crease of the first joint of the thumb in a seam on the ball.
Your fingers hold the ball—at least, mine do—so that there is daylight between my palm and the ball. I get a better feel—a more delicate one—this way. But, again, some palm the ball.