I've realised a few people don't know about the /focus command that was implemented into wow a while back, so I've dug up an old post on it. It's particularly useful for healers, or for anyone with a single-target CC ability that needs to be refreshed midfight. This command is most useful if used in conjunction with an addon like xperl (my favourite) or perl_unitframes. I'll explain why below.
It is now possible, either in a macro or as a simple typed command, to /focus on a target. This 'saves' that target as your focus. The command /target focus will change your target to your current focus. For example, the following macro will set your current target as your focus if you click it while holding the Alt key, or will target your focus if you click it without holding the Alt key.
/focus [modifier:alt]
/stopmacro [modifier:alt]
/target focus
Kinda useful for saving a target and being able to recall it later. Not the most useful macro in the world though. Here is a more useful one... Alt-clicking the macro will save your current friendly target as MA, and clicking without Alt will assist your preset MA.
/focus [modifier:alt]
/stopmacro [modifier:alt]
/assist focus
Not bad. But it gets more useful. 'focus' can be used in a macro as a valid target for a spell - so you can cast a spell on a preset focus without actually needing to target it. For instance, this spell for mages will set your current target as your sheep target if Alt-clicked. If clicked normally it will sheep your focus, even if you don't have your focus targetted - so you can keep your current dps target.
/focus [modifier:alt]
/stopmacro [modifier:alt]
/cast [target=focus,exists] Polymorph
You could tweak this with the appropriate spell if you were a warlock wanting to keep something banished or seduced, or a priest wanting to keep something shackled... or...
Anyhow, if you are a healer it is useful to keep your primary heal target focussed, so that you can keep an eye on their health even when you have something else targetted. This is mostly used to keep an eye on the MT's health, but it can also be useful in fights where you need to keep an eye on the health of an NPC, such as the last fight in Arcatraz.
Sadly, however, default WoW doesn't show a target box for your focus target, so I recommend using a good addon like xperl that will do that for you. In fact, I can't recommend xperl enough, it's great. This was my UI at level 60 using the perl_unitframes addon, which is pretty similar (I should probably make a picture of my current UI). Across the top, from left to right, are me, my current target, target of target, target of target of target, and focus target. I love it.
Anyhow, hope that helps some people. Check out the UI & Mods official forum or the Most Used Macros on WoWwiki for more info.
