The User Interface (U.I.) in World
of Warcraft is often touted as the pinnacle of modern MMO gaming interfaces.
Without a single addition you may find the game to be entirely user
friendly and work towards your goal of melting faces while drinking
ale and shouting loudly over voice chat. If you're a casual player or
a raider you may want a little bit more from the interface. That's what
MMOs are all about anyway, the continued advancement and perfection
of your character. That or you know socializing and playing with other
people but you can do that later!
As for a Mage there isn't a lot of Mage specific U.I. functions. Mages only have about 3 things to worry about that U.I. mods can improve. Sheep, Improved Scorch, and Missile Barrage. These things can be manually timed or watched for, but there are a few U.I. mod options to kind of help. There are also a lot of general mods that can help make your U.I. sparkle in the sunlight (err I mean be shiny and glittery, your U.I. is totally not a vampire).
Scroll down to see the big hitting Mage mods.
These are mods that every class can use, but are still good for the Mage.
Bartender is the mod I recommend for organizing your action bars. The reason that as a Mage you need the bars is because you have A LOT of spells. You have mana gems, portals, crafting, lots of attack spells, lots of situational spells, and just a lot of things for action bars. Bartender3 lets you move your bars around, make new ones, and lets you have a very complicated set of keys for using your abilities.
I recommend having your rotation bound to the keys you use most. Like 1-2-3-4 or something along those lines. You can then use a combination of SHIFT, ALT, and CTRL to make a lot of cool buttons. For instance I have Living Bomb set to T while I have Remove Curse on Shift-T. These abilities are also sprawled across my desktop so I can watch cooldowns or utilize the mouse to click them if I need be.
A lot of the functionality is kind of built into the client now, but the amount of customization is limitless. I highly recommend having all of your portals on a bar with Dalaran and Ironforge/Orgrimmar as big buttons and the rest as smaller icons. Put your rotation as big buttons so you can watch cooldowns and have all of your buffs on their own section. Then put your AoE abilities elsewhere and then put all of the "trash" like ST spells that you're not spec'd for elsewhere. Never know when you'll need them.
Bartender3 will grey out things that you're out of range for or don't have the mana. So if you're out of mana and need that one spell cast you can easily find something that you have the mana for. Overall this is an excellent mod for every class, but Mages can get a lot out of it.
X-Perl Unit Frames
There isn't a single Mage specific thing to X-Perl other than it shows your debuffs bigger than others. This is important for things like Improved Scorch or watching your snares. It also has excellent raid bars and lot of helpful U.I. settings for raiding.
No class should be without Omen or an equivalent threat meter. The game might have threat built in, but it's good to know what your threat is on some enemies. You might not easily pull aggro off of a boss but a Mage can pull aggro off of adds easily. It's great when soloing with the Water Elemental too if you want the Water Elemental to tank a little bit.
You need to test your rotation and glyphs and there is no better DPS meter in my opinion than Recount. If you only enable it to go to the target dummies then that's fine, but it's also good to see how your damage stacks up to the rest of the raid.
Mage Specific Mods
These are more specialized Mage mods.
This mods usefulness changes depending on what your spec is and if you're sheeping things, but that won't change how amazing this mod is. This is basically a casting bar replacement. It replaces your generic casting bar with a timer (showing how many seconds you really take to cast) and will show a timer on the targeted unit with how long your buffs or debuffs are lasting. With Improved Scorch this is critical because you need to know when the 30 seconds are up. You can use it to see when Sheep is ending. In some boss fights there are debuffs that take down your casting speed and with this you'll immediately know what's up.
This is one of the better mods to have for a caster and I highly recommend it. You shouldn't need to even adjust it. It works right out of the box for most people.
Mages only come with Remove Curse but Curses are not that rare. With Decursive it becomes easy as baking a frozen pie to decurse your entire raid. Just click one of the buttons that have a curse on them and you're good to go. In the rare instance that someone is aggressive to the raid (through mind control) it'll give you the option to sheep them!
This little known mod will pop up a box whenever one of your abilities like Missile Barrage come up. It's pretty handy, but not very popular. Scrolling Combat Text did a good job of alerting you when Missile Barrage/Brain Freeze/etc. came up but it hasn't been updated lately.
There are other mods out there that are helpful like DoTimer, but they are more work to set-up and use than just keeping the time running in your head. Mages are gifted with the fact there isn't a lot going on that they have to watch so there isn't a lot of things to manage.