all posted above is about being athletic/having athletic body... it does not warrant nor promise pace... for pace only a smooth and proper run up will help you get there (Especially at club level)... guys have faulty run ups without any thought behind it, work on that, first and fore most work on your run up, once that is done you can than automatically find increased pace from what you were originally doing. (having an atheltic body only helps so yea, dont throw that out of the window)...
Run up means,
still head, smooth rythem in the run up (body should not be all over the place), start slow and accelerate and your last few steps should be the fastest, (most guys start fast and slow down to even a complete jerk stop at times before delivering)... or your run up should be smooth throughout its duration (ala M asif)... your hands positioning is very important as well, as to where they are, (alot of guys have them flailing around, or too stiff, or move them up down or around unnecessarily), and then a good follow through to finish it off, after pitching dont just do a jerk stop, continue with the flow of the run up... holding the ball is very important too, a lot of guys hold it wrong, there should be a finger's gap between the ball and your thumb webbing once you hold it, also think of the ball as an egg, that when you hold it you should not end up cracking it, not toooo ultra light, nor toooo tight, just light enough that should someone do a light tap on your hand the ball should fall out... gripping the ball very hard/stiff will cause more friction out of the hand thus reducing the pace...
that is the very basic, after that it is about having the person next to you to be coaching them or them practicing it diligently, don't expect to have it mastered in a day or a week, sometimes it takes even a couple of seasons, just relax work hard on it, things should start to improve after some time.
Good luck...