I am trying to improve at PvP by watching skilled players play. One day, watching Qwneer play 3v3 on his warrior I noticed that he was almost constantly swapping his Focus Target without actually right-clicking the Gladius frames ( the only way I know how to set Focus Targets )
Basically the situation was:
He had a Shaman both on focus and on target, next thing, he had a warlock on focus and was intercepting him in order to stop his cast... Didn't notice any particular button usage too, as he has the glow-upon-click effect on the SnowfallKeypress Addon.
there is addon called Focuser, when u Ctrl+Click on anyone it became your focus target, also u can use macros like /focus arena1 /focus arena2. Or if u want u can use this macro which simply change main target to focus and reverse