Big Hit Box

Aeltyra is the author of the fairly casual rogue blog 'And Two Rogues' and can be found on EU-The Sha'tar, a roleplaying server.

I thought I'd write up some really basic tips for the people that like to join the fight up close and personal, perhaps for some of our newer melee brethren.

A dead melee does zero DPS.
I hear people in the back yelling 'durr' (hi mom), but let's face it - as DPS we are often told that we are expendable, and although we're not last on the list of people to heal (that's ranged DPS, HAH), we're not really top priority either. In other words, don't do anything stupid. You can explore that thin line between being hit by an AoE and DPSing the boss, but don't overdo it. Get out of there in time. Don't be a hero with adds.

Ride the aggro ceiling
Isn't that the most fun expression ever? Anyway, the aggro ceiling is where you are just below the border of overaggroing. As tanks gain more threat, the ceiling goes up and you can DPS more. Depending on your class and your tanks, you may not have to worry too much about aggro, for example rogues using vanish offensively (to benefit from overkill) will probably have a really hard time overaggroing after that vanish unless their tank fell asleep.

Melee does it from behind
Doesn't have quite the same ring to it as the song, but it's true. DPSing from behind eliminates the boss parrying you. If a boss parries your attack, or someone elses, their attack speeds up for that parry. If this happens multiple times (because of other melee and the tank being parried by the boss as well) you can get a 'parry bomb', a deadly string of sped-up boss attacks that squash your tank like a fly.

Don't stand in the [color] stuff unless told otherwise.
Flames, goo, black holes, swirly purple stuff: it will all rip you to shreds if you don't get out of there. This is especially problematic for us melee because we're usually all fairly close to eachother and stuff on the ground is harder to see. So don't get tunnel vision while hacking away at the boss or you may end up dead.
Obviously, there are exceptions, like the spark residue on Malygos that increases your DPS.

Mind your surroundings
The default melee view is a huge ass anyway, so you may as well look the other way, check if the healers aren't being smashed by adds, if there's a wall of deadly lava coming for you, and so on. You don't have to look away from the boss all the time -it's useful to see what you're hitting too every now and then- but there may be other areas you are needed more.

Help out where possible
Sure, you're melee DPS, but it never hurts to help out with something else either (unless you're fighting enrage timers). Throw a battleres, throw a FoK with Anesthetic Poison, maybe cleanse another melee or throw a heal on yourself. These little things lighten the load on other people, and they barely have an impact on your rotation or your DPS.

Have fun
Don't be too serious when raiding - having fun is still the most important thing about this game! Some people resort to practical jokes (har-har, Tricks of the Trade on a Hunter), others prefer sarcastic humor or some dirty Ventrilo jokes - as long as you're having fun with your friends, that's all that really matters. Don't make your WoW role feel like a job or you'll get tired of it really soon and burn out.

That's all I can think of at the moment. Comments greatly appreciated - I'm still practicing on writing for an audience, so yeah.