At the moment of release you must be stretching the bow, forwards and backwards equally. To do this you must be using the 'pulling' muscles of the back and NOT the 'holding' muscles of the upper arm
*. It is harder than it seems to maintain the pulling while at anchor, very easy to slip into 'holding' (
especially if tired). But this is what must be done while taking the time to refine your aim.
Once the aim is as good as it will get (and it will be wobbling around- don't try to stop it totally), then the feeling
* of further back and forward expansion is used to trigger the release. The follow-through is a natural side-effect of the continued use of back tension. You don't practice your follow-through, it happens. What you practice is pulling with the correct muscles while keeping your draw arm and hand relaxed so when your release occurs the follow-through is automatic.
* The actual degree of movement that occurs in expansion is very small, so the 'feeling' of expansion is your guide to knowing you are getting is right.
* If you see someone who's release is a horizontal salute, that's a 'holding' release. And a lot of good archers do it.
Rod Jenkin's mantra of 'Excessive pulling to anchor. Balanced pulling at anchor. Increased pulling (expansion) to shot conclusion.' is a way of saying what I just have ...... in a way Tradarcher would appreciate.
Anyhow, got side-tracked, what I meant to say is that if you use correct back tension AND keep your draw arm relaxed your release WILL be clean.