Some (maybe basic but often negleced) notes about playstyle (written for Warlocks – maybe useful for all)
Within the last weeks I was asked by a couple of other locks how they can improve their dps. They were already using the right spec, had the right gear/gems/enchants and were driving the “correct rotation” whatever this means. Still they did not manage to get the numbers they expected to get. So I gave them some tips and tricks which, I believe, can make the difference between a good and an exceptional player. I am not saying that those will make every bad player a good one, but they can help a little if you got the necessary talent for it ;-). Since I am a lazy pug I now wrote this short guide to avoid telling the stuff over and over again in whisper. Maybe it is interesting for the one or the other player.

General Advice
You have to “feel the game”. Be water my friend! When I play I do not have to concentrate or watch my spells nor I have to have to think which button to press. I just play the game. I am one with my character. Keyboard and mouse are just means to an end. This feeling is just reachable through practicing. Practice until you are one with the game. You shall be one with the game – not just a player. This does not mean you have to play 24/7 nor that you have to be addicted to it. But if you are logged in you should play like it is all in your life.

Now to “the less spiritual hints”.

I see many players around who disregard movement. Even though World of Warcraft is an MMORPG and movement plays a less important role than in first-person shooters it is essential. If you do not have a clue what I am talking about go and watch some counterstrike or quake matches. You will see that the top players move in a different way than the less good ones. Movement is part of tactic, avoidance and placement. This is the same for WoW. This comes to an absolute point when you have to move at encounters in order to avoid fires e.g. but is not less essential in general. As a caster you should in general move as less as possible. Moving time is casting time and casting time defines your possible dps. Whilst moving you still should use your instant spells like life-tap or corruption for warlocks. Also you can do small steps on global cooldowns. During that time I run most of my ways at encounters. Furthermore you should place so you do not get out of range. As long as the encounter does not require you to stand on a specific place it is best to stay at max-range. Think about how you can improve your movements and I am sure you will find some situations where it can be optimized. Always keep in mind that movement is important. Do not disregard its role.

Don’t die!
Maybe the most important rule. Never Die. You can not dps while you are waiting for a ress or running back into the instance.

Play the team game
Of course it is nice to have a big epeen for being #1 at meters. But trust me, the sex will be much better if you additionally have good partners. Those partners are more happy if you help them. So be nice, friendly and helpful. It does not hurt you if you sometimes pull an add from an healer or crowd control a target which is hitting you group – even if you are not assigned to do so.

Push the shiny buttons quickly
Do not waste time! Never! When one spell runs of you should already cast the next one and so on. Being slow is your decay. A good cast bar mod (like AZ Castbar or Quartz) can help you to improve your spell placement. It is also very important that you cast your spells in the right moment. Let dots tick for the whole range but have them up again the same moment they are running off. Do not react - be farsighted. You do not have to wait until a spell/dot/cooldown runs out and think afterwards about if you should recast it. Knowing when to press which button even before you have to is the key to high numbers.

Use what the game offers you to use
In general clicking is slower than pressing mouse buttons. Also, since you need to use your mouse for other things while playing, it is better to do as much as possible with your fingers. Use all buttons which are easily to access to you. For me that also includes my two additional buttons on mouse. Separated from my other commands via keyboard I can give input like send my pet in / use my target macro e.g. This leads us to a downside of being human: We just have five fingers or limited range. Thus you should bind all often used spells that they are good to reach. Have “accident buttons” near to have fast access – for me that’s a Fel Healthstone bind on Q for example. Also keep in mind it is possible to double bind buttons with the help of marcos or bar mods and access them via Shift+/Ctrl+/Alt+.
/cast [nomodifier] Demonic Circle: Teleport; [modifier:shift] Demonic Circle: Summon
This helps to overcome our disadvantage ;-). The first times you play with new bindings it will be strange and maybe you will have trouble to get all spells placed. Do not worry. You will get used to it very fast and in the end it all works automatically.
If you want to learn more about bindings id recommend the following guide: Keybinds and you

While some macros are just useless (like those one-click-all-spells-ones) using macros can raise the effecienty of your playstyle. Best example are targetting macros which help you to find your targets faster.
/target Nether
/stopmacro [nodead, harm]
/target Infernal
/stopmacro [nodead, harm]
/target Mistress
/stopmacro [nodead, harm]
/target Lord Jaraxxus
/stopmacro [nodead, harm]
Your User-Interface is your direct visible (and hearable) interface to the game. Of course you can also play with a standard or messed up screen and it may not affect your personal playstyle at all. But why drive a 20-year-old trabbi if you could use a new porsche?
Your User-Interface should be optimized to your need. Display all necessary information so you can easily see them without having your eyes wander too much moving around. This saves some milliseconds of time and you can be much more focused on your real job. As there are already many good guides for user-interfaces and premade user interfaces around I will just post a guide and some interfaces I rate as really handy: Guide: What to aim for when customizing your UI

Toodels Warlock UI (my own one)
Damia Ui

Last thing I want to pronounce here is the use of Power Auras Classic. This mighty addon gives you the opportunity to create custom visible and hearable warnings which can be very very handy to make essential buffs like the Hand of Protection at Anub25 Hardmode visible. Extending this you can include important buffs/debuffs for most encounters.
More about Power Auras: PowerAuras Tutorial