I know a lot of people use Power Auras in PvE (some may even already use it in PvP), but I've found it's really helpful for using your trinket—or WotF if you're undead—shifting out of roots for druids, etc.
Here's a link to the download, before we get started.
So first up, let's talk about the configuration screen:
This is where every "aura" you create will be kept, and toggled on/off. As you can see from mine (going by icons), I have one for Slice and Dice, Blind, Roots, Fear, Cyclone, Polymorph, Shadow Dance, and Recuperate. Some of these are buffs applied to me, some are debuffs applied to me.
To create a new aura, press "New".
This is the screen that comes up. It may look confusing at first, but play around with it a little bit. You can always delete the aura you're messing around with and start again.
IMPORTANT NOTE: when making an aura, make sure your activation conditions are right! If it's a debuff applied to you, don't have the buff/debuff drop-down set to buff! If you only want it active in combat, don't have "In Combat" X'd out.
A red X in a box means that the aura will turn off even if other conditions are met. For example if you put a X in "In Combat", you will NEVER see the aura that you're making in combat. Period. These conditionals are explained in detail in their tooltips.
So let's set up an aura to activate when a warlock casts Fear on us.
I like the warning sign a lot. I use it for poly, cyclone, blind, and fears (in different colors, as you'll see). It can be nice and big and go right on top of your character so that it really gets your attention.
Basically, I want to see if I get feared no matter what, since I'm undead and have WotF, so I have this aura active for pretty much everything but when I'm in a vehicle.
That's that. Pretty easy setup when it comes to debuffs, since you want to see it no matter what.
Let's set up a buff and see how that works. I'm a sub rogue, so in PvP I like to see my Recuperate duration.
Pretty much the same thing as the fear aura, but I want to know how much time I've got left on Recuperate.
Here's where I really like Power Auras:
I can set up a timer to show up when my Recuperate is active. Options are pretty simple, you just have to know that the tab is there and how to use it.
Here's a shot of what I have set up for SnD, Shadow Dance, Recuperate, when when another rogue blinds me:
And that's pretty much it. Pretty easy, but very helpful in PvP. I can trinket/WotF almost instantly because of Power Auras.
I'll likely be continuing these "lessons" eventually. This was in response to a couple people asking me about addons I use in PvP. If anyone has requests for further stuff, let me know.