I have some branches of my azaleas that have 4-5 offshoots perhaps a foot above the plant. Not sure why it does this or where to prune.
You can shorten the branches anywhere that pleases your eye if you wish. Azaleas differ from rhododendrons that they have dormant buds all along the lengths of the stems and not just at the point of leaf axils - they will sprout from just below any cut you make.
Immediately after bloom is the best timing.