1. Back up your Interface and WTF folders.
For any major addon, interface or UI change, this is step one. I keep a copy of my Interface and WTF folders updated all the time so that I can revert to previous settings if I need to. Those folders house your addons and all their settings, character by character.
You need to keep a copy of the entire of both folders somewhere else on your drive, not within the World of Warcraft folder within program files. Depending on how much you have in those folders, it may be a fairly lengthy task to copy it all over, but it's very much worth it. I keep mine on a USB flash drive in case of computer failure, so that I can restore all my addons and settings in one fell swoop and put them onto a new computer if need be. Yes, I really am that sad!
And for all you naysayers, yes, you might be copying useless information that won't be relevant any more past the end of Cataclysm, but it doesn't hurt to be prepared if it transpires that you actually can reuse your old settings.
2. Set up a standard UI.
This is the simplest step you can take to make your life easier, and it's a fantastic idea to have this set up for at least your main character, if not your main and first alt. How do you go about doing this? Well, it's really simple. Just grab Addon Control Panel, and use it to switch off all your addons.
All of them? Yes. Absolutely all of them. Even Recount or Skada. Even DBM. Even Auctionator. Every single thing has to be off. Then have a little look at what you're left with. If, like me, you use Bartender, you'll probably have a whole bunch of messed-up keybinds and a bunch of mysteriously absent bars. That's OK. It'll be fine. This, ladies and gentlemen, could well be the only UI setup that works for you come Mists. So make it playable.
Please note that doing this could well mess up your Bartender or similar bars that you took so long to craft. Bartender, certainly, bases much of its setup on the Blizzard UI, but from my experience, it's far easier to set up the stadard UI, then tailor Bartender to your needs than the other way around. Furthermore, you know the standard Blizzard UI will work; you don't know that your action bar addon will.
Make sure that your bars are bound logically, similarly to your usual UI if possible, and make sure that your bags are arranged in such a way that they'll function for you as five separate bags. The same applies for your bank.
Now is also the time to ensure that you have things like debuffs switched on, that your party frames are set as raid-style if that's your thing, and that your unit frames work as best they can for you.
3. Work out what you really need plus some alternatives.
Let's face it, you don't really need all your addons. Many of them are purely cosmetic and added little fun things. You don't really need a kgPanel behind your bars; sure, it's nice to have that, but is it necessary?
The follow on from step 2 is to work out which of your addons you really struggle to play without. For me, that's an action bar addon, a bag addon that also adapts my bank -- and that's about it, to be honest. Yes, I would like to have many, many more addons, but that's what I actually need. Playing on the beta (for those of us who have been able to access it) is a great way to work out what's really necessary, and what I've discovered is that the answer to that question is "not that much."
If you're not really sure, follow step 2 for a few days and see what you're really feeling the loss of. Those are your key addons, the ones you need to get sorted out as soon as possible. The pretty stuff and the extra stuff can wait.
What then? Well, go online and find alternatives for your most-used addons, alternatives that are being updated, or have been already. If addons are stable on beta, chances are that their developers are ahead of the curve enough that they'll be stable for patch 5.0.4, although there are absolutely no guarantees.
4. Keep an eye on what's being updated or what has been.
Many addons are already running smoothly on the beta and, as I mentioned, are therefore likely to be working come patch 5.0.4. Work out what those addons are, and if you find them, let me know, since next week's Addon Spotlight will be a list of addons that are stable and addons that will be stable and updated for patch 5.0.4.
How do you find out what's updated? Well, check out places like Curse or WoWInterface or WoWAce. Go back to step 3 and remind yourself of what your most needed addons were, and look for those addons or similar ones.
If you're lucky enough to have beta access, that might be a good way to check addons are working. If they work in beta, they may well work in 5.0.4, but there's a good possibility that they won't. It's a bit of a funny period for addon developers, as they have to prepare for Mists, but this period is not quite the whole transition -- it's leftovers from Cataclysm with some bits of the Mists stew thrown in, and it's so short-lived that many addon authors won't prioritize it. Having said that, if you've got access to the PTR, that would clearly be an excellent way to test out updated addons.
If you take either of those steps, I'm sure addon creators would be very happy to have your feedback on any bugs or glitches you find.
5. Think of Mists as a clean slate.
I tend to let my system become a bit bloated, particularly recently as I've been trying out many a new addon for Addon Spotlight. But even before I started writing this column, I was forever trying out addons and UI replacements and the like, and I am ashamed to admit that I don't often completely delete them from my system. Having quite a powerful computer hasn't aided this at all, as I seem to be able to run WoW without any trouble, even with a million addons slowing everything down.
So, the enforced change that is Mists will be a good thing for me. It'll force me to remove some of the extraneous addons and maybe think about some replacements. It'll allow me to pare down my UI to the things I really need, rather than having it cluttered with programs that I won't really miss if they're gone.
If you think of Mists as an opportunity to start again, maybe you'll be excited about reworking your UI rather than being frustrated by it! I know that's the approach I'm trying to take.
6. Be patient.
This last tip is kind of self-explanatory, really, but be patient. If past pre-patches are anything to go by, various things will go wrong and won't stand up to being unleashed on the entire WoW community. Some addon developers are really ahead of the game here, but if Blizzard implements last-minute changes that affect the code used by the addon creators, it can take them a little while to sort it out.
Remember that many of these addon developers do it outside of full-time jobs and have lives around WoW. Be patient. Don't go on their forums and rage at them, and don't discard an addon just because it doesn't work perfectly the very second you install it.
Addons are what we do on Addon Spotlight. If you're new to mods, Addons 101 will walk you through the basics; see what other players are doing at Reader UI of the Week. If there's a mod you think Addon Spotlight should take a look at, email firstname.lastname@example.org.