The important things are always simple
There is no perfect magic trick to winning an arena fight. There isn’t a certain combination of spells that requires a warlock specced exactly 40/0/31, a fury warrior, and the mage trinket from Heroic Whatever that guarantees a win every time.
The advanced strategies are merely the basics, just with macros attached to them.
The simple things are always hard
That isn’t to say it’s easy; not by a long shot. Is it hard? Blimey, of course it is. It’s difficult to pull off a proper CC train. It’s difficult to pull of a target swap at the right time. It’s difficult to counter a CC train. It’s difficult to survive a target swap.
Yet the strategies you need to win, you probably learned before you acquired your first mount. You need only master them.
If at first you don’t succeed, bring bigger guns
If a something failed, it’s in your best interest to not try it again. At least, not the same way. If it failed, there’s probably a damn good reason why it failed.
Some famous guy at one point probably said something along the lines of “doing the same thing twice, and expecting a different result is the definition of insanity.”
Your tried and true target swap fail to kill the healer? Then it isn’t tried and true, is it? It’s tried and failed. Try a swap to something else. Don’t swap at all. Use a different CC order. Use a different attack order. Wait for X and Y to be Zd.
You are not Superman
Arena is team-based. It is not you versus them, it is your team versus them. You don’t see Death Knights soloing Patchwerk, you don’t see a hunter pulling Vanndar when they’re alone. Those are stupid risks.
Stupid risks cost you. They cost you matches, they cost you points. Don’t take stupid risks.
Remember, “alive” and “hero” are mutually exclusive terms.
Teamwork is essential
I really can’t stress this enough. Use voice! Vent, Skype, even the in-game voice system if you have to. You must be in constant communication with your partners.
Call EVERYTHING out. Every CC, every major event. Call out when you summon a water elemental. Call out when they summon one. Call out when you Counterspell the druid. Your druid needs to speak up when he gets Counterspelled. When the rogue uses his trinket… say so!
Cover your friends, so they can cover you
Put symbols over your entire team. People lose arenas because they lost LOS with their own team just as often as they lose LOS with the opposing team. Try to mark everyone the same for every arena battle. If the Paladin is always star, for instance, it just makes things easier in the long run.
It’s important to know where your friends are. You never know when they might suddenly need your help. If you can sheep that warrior beating on your warlock friend, now that warlock is around to fear that rogue off of you.
It isn’t stupid if it works
Calculated risks, on the other hand, can win you matches and earn points. Suddenly doing a target swap to the Paladin when he’s out of position? Good idea. Charging the Paladin, by yourself, when your partner is out of position? Bad idea.
There’s nothing wrong with taking risks. It’s the stupid ones you need to avoid.
If it’s too good to be true, it’s an ambush
Always be alert to changing strategies. Arena isn’t a boss fight, where you can rely on Deadly Boss Mods to tell you when you need to sacrifice the first Cultist to C’thulhu. There are no guarantees, no “at 40% he summons Shoggies”. It’s just you and your abilities versus them and their abilities.
If you can suddenly do a target swap to somebody else, so can they. You’re not following a script; neither are they.
No plan survives combat
Whatever careful strategies you have planned, whatever brilliant tactical moves you have designed, be prepared to discard them all immediately. There is no such thing as a perfect plan.
If your strategy hinges on them attacking the mage… what if they don’t?
If your strategy counts on the shaman being the CC target… what if he isn’t?
If your expecting a target swap to the rogue… but instead the rogue gets CC’d, what now?
If you ever answer “Uhh…” you’re likely already dead.
Arena is just as much about reacting correctly as it is about acting correctly.
Everything you do can get you killed
This includes nothing. You’re in a situation where every GCD counts, every movement, every repositioning, every cooldown used or not, makes the difference between destruction and victory.
You will make mistakes. It’s impossible not to. Minimize your errors as best you can. Speak up if something goes wrong, recover from it if you can. If not, learn what went wrong, and then avoid every doing that again.
Nobody really cares what you did ten seconds ago, and nobody cares what you’re thinking of doing ten seconds down the line. All that matters is what you’re doing now.
And when (not if) your opponents screw up, capitalize on that as much as you can.
Your tactical decisions are made by your enemies just as often as you make them.
The enemy never retreats
Your opponents will never run and cower in a corner. They never balk at the size of your sword, or flee in terror. If the opposing team is running away, they are merely playing defensively enough to regroup. They aren’t retreating, they are simply making a tactical withdrawal to try and get into a better position.
This is the arena. If you have concepts like “sporting chance”, “mercy”, or “honour”, please leave them at the gate. There is no such thing as a fair fight, merely the fights you win, or the ones you lose.
Experience is something you don’t get until after you needed it
There’s only so much you can learn from watching videos or reading blogs. All these sources can really do for you is set a foundation for you to build on. There’s nobody in the arena holding your hand.
The only way you’re going to get better is by practical experience. A blog can’t teach you how to get a smarter reaction time. You can’t learn how to not panic from watching a video. A guide on some forum somewhere isn’t going to be able to teach you how to not freeze up.
If you’re thinking clearly, know exactly what’s going on, what the next step is, and have total control over the situation… you aren’t in combat.
After every arena battle, take the time, even if it is only a few seconds, to go over what went wrong/right/well/crappy and what to do in order to be better next time.
The mark of a true gladiator is the use of judgment to avoid situations which require his superior skills.
~ Probably an orc
Critical QQ 
Every time I read one of your PvP posts I picture two players at their computers hundreds of miles away fro one another. Both players wait for the gates of the arena to open to enter into mortal combat with the other. I can almost see the organized chaos as it unfolds in the arena as one side eventually emerges victorious and the other licks its wounds preparing to battle at the Arena Master.
Two teams, two people, Alliance and Horde, both comparing mental notes about their own performance and how it would be rated by the author of the blog they both claim as their favorite…Critical QQ.
That would be extraordinarily creepy.
Obviously my response would be “DEATH TO THE ALLIANCE!”
/quote
You don’t see Death Knights soloing Patchwerk
/quote
a rogue soloed patchwerk newly 😛