It all starts off with a flip to bear and if you stuck talent points into furor you get a little bit of rage to start off with. If you don't have 5 points in furor then you might not, but go ahead and try again; bears don't need no stinkin' mana anyway. Using enrage will add even more rage to start out with, but be careful with it as you take more damage when it is active. Most times the little bit of rage from Furor or whatever you have left from the last fight is enough to just charge in and go nuts.
Or maybe not, you remembered to buff yourself before you flipped to bear, right? No? Well darn, put thorns up on yourself as well as gift of the wild unless you have someone else taking care of it. There are some resto and balance druids out there that think they are doing you a service by casting thorns on you, but honestly how many of them can be counted on to refresh it every 10 minutes. I prefer to use my glyph of thorns for an hour self buff and not worry about the little bit of extra damage I could be doing some of the time when someone else remembers to buff me.
Most pulls will start off with some combination of feral charge, feral faerie fire, growl, demoralizing roar and swipe depending on the situation. The idea here is to get everything you are going to pull interested in you and keep your healer from pulling anything you hadn't gotten around to hitting. This happens very quickly and with good reason, you want to be done before anyone notices what you did. There are going to be DPS trying to do the same thing a second later and it is your job as a tank not to let them.
That isn't to say DPS doesn't have any responsibility not to pull things away from you; they do, but they will still do it on occasion. Even the best tank can't hold everything all the time and it isn't anything to worry about, unless it went after your healer and then you suck. Actually that happens sometimes too.
My main defense against overzealous DPS is to put a skull on a single target. Sometimes it is a priority target and sometimes I just put it up to give the DPS something to look at. Basically if all the DPS go crazy on one target while you are busy dealing with others it makes your job easier. It is relatively easy to stay ahead on threat on one target and worst case scenario you only have one thing to taunt if it takes you a little more effort than expected to corral everything.
While your DPS is concentrating on skull and and everything is under control you have some time to start building threat on everything else. Once skull dies you have two options: you can decide you have enough threat on everything and it doesn't matter what anyone kills or you can mark another skull and continue working. Depending on your group you can forgo the skull entirely, only marking priority kill or crowd control targets when applicable. Sometimes if everyone knows that mob X does something terrible they will attack it first and you don't have to worry about marking at all. I recommend a macro for marking a skull just to make things easier and 99% of your marking will be just that macro. You can find that macro as well as others in my listing of macros linked on the right.
I totally glazed over the whole pulling and whole making threat portion of that when it came to which abilities and when so lets fill that in now. First you have to get in melee range of your target(s) and for that there are two options: you feral charge or run in to them or you feral faerie fire and/or growl and make them come to you. It all depends on the situation. If there are casters in the group they generally wont come to you unless you hide behind an obstacle like a wall or column. That is called a line of sight (los) pull. Generally with casters it is easiest to just run in to them, but if there are other mobs around you dont want to pull or multiple casters spread out then it is often easier to bring them all together to you by getting thier attention and turning a corner.
If you just run/charge in you will start with demoralizing roar, which will reduce the damage things hitting you can do, and swipe to hit everything around you. You'll then position yourself so that everything is in front of you spamming swipe all the while as well as other focuses attacks as needed. If you marked a skull for example you are probably going to need to hit it with more than just swipe. When you are letting things come to you the process is much the same except that you might just want to swipe and then demoralizing roar only after everything is around you.
For your more focused attacks you will be using mangle and faerie fire every time they are up in addition to lacerate which you spam while mangle and faerie fire are on cooldown. You will also refresh demoralizing roar as needed. Your primary threat/damage generator is maul which you queue up for your next autoattack which it then replaces. Basically you have a button to hit every single potential white attack, but of course that is stupid so instead you will include it in macros combining maul and all your other attacks and forget it even exists. With one minor exception if you have the glyh of maul, which most tanks will, you will have to keep in mind you will always be hitting two adjacent targets. I have my macros set up so that if I need to I can hold down a modifier key like shift and not use maul when I need to only hit one target when there is crowd control nearby or such.
So here you are in a puddle of mobs making sure they stay where you want them. You should cycle through them by clicking or tabbing to see if any need additional threat and in general just to bop them on the head a couple times for good luck. Should one run away you can growl to bring it back and them make sure to whack it good and hard so it sees the error in its ways and doesn't try it again. Ideally we'd hit the DPS, but that is an invalid target. In addition to growl which only matches threat of whoever pulled it you can faerie fire it as well to put yourself a little bit ahead.
If your growl is on cooldown and you like that DPS enough to not let them be pummeled then it is time for a field trip. Charge the mob or run after it being careful to strafe to avoid being hit in the butt too much and set up shop again once you have it. Tanking is a very fluid process and a lot of what you do is in reaction to changing circumstances.
Sometimes you will have adds come into play, sometimes body pulled, sometimes part of the fight and sometimes they are close and you just want to hit them. If there are only one or two you can generally faerie fire or growl at them to get them to you if there are more or they are casters and don't more you will have to run over and collect them like you would any other pull instead of treating it like someone pulled it off you.
There are occasions where you can't get everything together and you are forced to tank a couple casters in two places at once. If your DPS is concentrated on one like they should be then you can concentrate on that one and use faerie fire on the other to keep it off the healer as well as staying ahead of any splash AOE damage that might be hitting it. If DPS are hitting both then you run around like a crazy bear and try and keep them focused on you. That would also be a good time to pull out that skull macro and mark one hoping they take the hint.
So basically being a bear means spamming a lot of buttons and keeping an eye on things. It doesn't even really matter what buttons you use half the time so long as you have things under control. Over time you will develop a sense of when certain abilities are better than others, but it always depends on the situation and how you are feeling that day. Sometimes you just want to hold threat and other days you want to try and out DPS everyone at the same time.
Now that you have a bunch of things hell bent on beating you senseless you have to think about staying alive. Sometimes you know when you are going to take more damage and sometimes you don't. For the times when you know it is coming you can make sure you have a cooldown ready to use to negate it. Otherwise you use your best judgment of what to use when and how many defensive cooldowns to blow at any one time.
Your most commonly used cooldown is barkskin for a straight up damage reduction for everything that ails you. It is on a relatively short one minute cooldown with can be shorted further with a set bonus. It is good to use even if you notice someone else is getting low and you are taking constant damage just to take pressure off the healer(s).
Next up we have trinkets which are generally on a two minute cooldown and have a variety of effects. The ones we are interested in using more often are the ones that increase armor or dodge and those that absorb damage. The trinkets that restore health of award temporary hit points are useful in other situations mentioned later. These trinket cooldowns require a little more thought than barkskin which helps with everything for example an armor increase isn't going to help with spell damage. When a trinket is applicable to you current situation use it like you would barkskin, but more sparingly. If things are really bad you can use barkskin and a trinket at the same time.
Our last line of defense is survival instincts and frenzied regeneration both on three minute cooldowns. They are most effective when used together, but it is often beneficial to save one when you can. For example if you healer goes down and death is imminent use both, but if you took a couple big hits in a row and your healer has been keeping up otherwise then just blow survival instincts and save the frenzied regeneration. Frenzied regeneration on it's own is still a very powerful cooldown and even better when coupled with the glyph of frenzied regeneration which increases healing done to you while it is active. Which means anything a healer does to you in that time is amplified. Trinkets which temporarily increase your maximum health are also good to use before frenzied regeneration since the amount healed is based on your total health.
The hail mary saves are healing potions, healthstones and any other trinkets or items that restore health. When you are getting really low and are pretty sure you will die then the few thousand health granted by these items just might be enough to give your healer time to get a heal off. There isn't really benefit of using these at any other time as the amount healed just isn't enough to warrant it and then you'd of lost the ability to use it later in the fight when it might help.
One of the most important parts of being a bear tank is to remember that you are also a druid and have more flexibility than any other tank. For starter if you are tanking an instance with someone else you can flip to cat form when not needed to tank for extra damage. Given our wearing a lot of DPS gear to tank and the fact that many talents are used for both tanking and damage we can put out pretty good DPS in a tanking spec and tanking gear.
Sure you should be in bear form whenever you are being hit, but sometimes for a pull of a lull in combat while a boss ignores you to do something there are opportunities to use other forms and abilities.
Before a pull you know if going to have a lot of up front damage you can hot yourself up.
You can use cat form and dash when you need to be somewhere in a hurry. The best use of this I have found so far is in violet hold where you have the portal on the far left that spawns a patrol that splits into two directions. You can cat dash from the opposite side and flip to bear to catch them all in place before they split.
You can stealth to check things out around a corner or to mark before making a pull.
Balance spells can be used to pull targets from multiple places at once if you use a wrath on one, moonfire on another one or two, flip to bear and faerie fire a third or fourth before they reach you. There is always hurricane as well to AOE a group and pull them from a distance.
You can do your own crowd control by rooting, cycloning or hibernating to pull. If you have enough distance on your targets you can even do two or all three in a single pull.
When you find a moment you can resurrect your own healer in battle or innervate them if they are low on mana. Often there isn't the opportunity, but sometimes there is.
If things are going really bad and you think you can get away with it you can even cast tranquility and heal you entire party. Many bosses and mobs don't hit the tank all that hard, but pummel the party or raid which is a perfect opportunity to pop tranquility and heal yourself and those around you. Even if you take a little more damage you are healing yourself.
Still you are a bear most the time, but those few times you get to be a druid can really make a difference.