Some have been confused how auto attacks works locking on does not make auto attack start. You can dance around the mob and you wont attack until the action bar is on the screen you can tell when your char is ready to AA cause the name of the mob highlights red.
Also you can ready your attack to be ready from far away as long as you have the bar up from a distance and you will attack asap when you close in on the mob.
That is all hope this helps folks.