You can cleanse things, so do it
This is one that I see ignored by players of all classes way too frequently, and that bothers me to no end. You are a druid. You are capable of removing poisons and curses without dropping Moonkin Form -- so do it. Seriously, there are some very nasty debuffs out there, especially in a 5- or 10-man, and your healers may not always be able to cleanse every effect that gets placed on the party. Not only that, but they might be struggling with something far more important, like keeping the tank alive. You can remove these things, and there simply isn't any excuse for not doing so.
Even in 25-man raids, it is imperative that you remove what debuffs you can from your fellow raiders. I must just have Deathwhisper on the mind for this article, but the curse that goes out during that encounter is one of the worst debuffs a player can get in the game. It needs to be removed from everyone who gets it the moment that it's applied; as a balance druid, you can and should assist with this.
Typhoon does not make you cool
Typhoon is a very awesome spell. In ICC it has found many practical uses for the knockback effect on a wide variety of boss encounters. Even in a 5-man setting, Typhoon can really be a good ability to have. It is only in the hands of a good player that this is true, though.
Spamming Typhoon or just randomly using it as it please you is an easy ticket to pissing people off to no end. You might get some minor amusement from the frustration that it causes other players; the rest of us just think you're a jerk, though (and I will say plainly that I have no hesitation in using the vote to kick option or removing you from a raid if you can't learn the difference). Simply put, don't use Typhoon to be an ass; use it to be helpful.
If you see a mob running toward you, try and use Entangling Roots or Cyclone before jumping right to the Typhoon button. Yes, Typhoon is great for getting that mob away from you, but there's also the chance that it is going to hit a few unintended targets as well, which will increase the frustration of everyone.
That isn't to say that the knockback effect is always going to be nothing but trouble, even when used on an already tightly packed group of mobs. For example, the spiders in Old Kingdom have an extremely long cast time spell which, in heroic mode, deals 20k damage to a standard tank. That's a hefty amount for a tank who's just starting out, and even to a well-geared tank it isn't a laughing matter. I've noticed that while these used to be the prime focus target for everyone, people have recently slacked off and just assumed that the tank can deal with it. In this case, if the spider is going to get its cast off, then it might be wise to use Typhoon to interrupt the cast; just check with your tank first so he doesn't automatically assume you're just trying to be annoying.
Starfall is shiny but not needed
Starfall is one of our best abilities that we have now. The damage that it is capable of putting out is phenomenal and it is always a good choice to use it as often as you can manage it. That does not mean that you have to use it on every single cooldown, especially when dealing with trash packs.
Starfall has a huge radius, and having it pull additional mobs is a fast way to wipe your group if you aren't careful -- yes, even in raids. I cannot even being to mention the number of times I've seen balance druids use Starfall in the first room leading up to Marrowgar only to have it pull every single group that we've planned on skipping. Even if the group does manage to get everything down, you've just wasted a significant amount of time forcing your group to deal with mobs that they didn't need to and you've placed additional stress on your tanks and healers that they didn't have to go through. If you aren't positive that you can use Starfall without hitting an additional group, then just don't use it. As great as the ability is, it isn't worth the extra hassle that it can cause.
Barkskin saves lives
Druids don't have many defensive cooldowns, but we do have Barkskin, and it is a very useful ability to many settings. Especially true in raids but also applicable in every single-group setting out there, using Barkskin to help mitigate incoming AoE damage might not only save yourself, but it can potentially save other people as well. Lessening the amount of damage that you take is obviously going to extent your own life expectancy, but it also means that the healers are going to have to spend less time focusing their efforts on keeping you alive and more on other people, particularly the tank. Use it as frequently as you can, especially when you are expecting to take some massive incoming damage. There are multiple boss encounters that have very predictable bursts of damage to the raid such as Sindragosa, Festergut and the Lich King; making sure that you use Barkskin during these abilities is really going to help out your raid. Not only that, but the ability is off the GCD, so you don't lose any DPS time by using it.
Simply put, there isn't any reason that you shouldn't use Barkskin -- so use it.
Do what works for you
This is my last bit of advice for the day, and sadly it doesn't pertain to balance druids specifically. I often get lots of requests from people to post macros that they should use or asking how they should do key bindings or if their UI looks good (not that mine does, so these questions confuse me), and I can never really give these people a solid answer. The best that I can say is that you should do what is most comfortable. Some people like having everything macroed, some people prefer to use the scroll-wheel or shift-clicking and some people like running with the basics. There isn't really a right or wrong answer, just so long as what you do works. If you have trouble casting certain abilities or performing specific tasks, then maybe a macro or remapping your key binds will help with that; maybe it won't, though.
Personally, I don't use that many macros on my druid, as I just haven't found a use for them. The only ones that I do end up using are either targeting macros for specific encounters or communication macros for Rebirth, CC abilities, Innervate and having a pet attack macro planted in Wrath and Starfire for Force of Nature. Beyond that, I run a fairly lean setup as far as those things go. Other people find use from having many more, and that's what works for them.
When it comes to key bindings, I just use the standard number keys for all of my DPS spells while I have click bindings for CC abilities, decursing and healing. Getting a gaming mouse is a really good investment for a lot of people, as it allows for faster reaction times in a lot of cases. If player lag in causing you issues in getting things done, then you may want to consider investing in one and using it as your primary source of DPS abilities. Just always keep your key bindings comfortable, where you know you can reach them and react quickly. Just after remapping, it will always take a while to get used to the new location of abilities, but if after a few weeks you still find yourself having issues with using certain things, then you may want to consider relocating them somewhere more suitable to you. Never, ever let someone else tell you how you must have your key bindings set up; other people are not you, what other people do may not be what is best for you. Focus on what works instead.
Every week, Shifting Perspectives treks across Azeroth in pursuit of truth, beauty and insight concerning the druid class. Sometimes it finds the latter, or something good enough for government work. Whether you're a bear, cat, moonkin, tree or stuck in caster form, we've got the skinny on druid changes in patch 3.3, a look at the disappearance of the bear tank and thoughts on why you should be playing the class (or why not).