I'm a rather avid raider, putting in a solid 20 hours a week on my Warrior. One of the major things about the time spent raiding is that it can be very precious. There is only so much time that 24 other people, plus appropriate class substitutions, can be available each week. It's critical that the time spent raiding is used well.
Unfortunately, using raiding time well is about as much of a challenge as is downing Illidan. In preparation for this article, I've spent the past three weeks keeping track of the down time in raids. We raid Sunday through Thursday nights, from 7:30 p.m. to 11:30 p.m. We experience a downtime of about 51 minutes for each raid, which is about 20% of the time. Down time is defined as the time that my character is standing still, not attacking, not moving, and not being MDed to.
Is this a good thing or a bad thing? I'm not really sure.
Tip #1: Chain pulling
Personally, I do my best at the main tank to chain pull and push the trash through as fast as possible. This works out 99% of the time, however the 1% of the time it doesn't work out can grind the raid to a halt. Case and point: The trash to Supremus isn't too bad, and is a lot of packs where the MT, OT, and Pally tank each have some mobs to tank. There are also some ranged dragons that the Warlocks tank. These pulls can go very fast, and are very predictable. Pulling slowly we can do this in about 40 minutes, while chain pulling each group, we can push through in 15.
Tip #2: Fully self buffed, all the time
It doesn't take much to buff yourself. Every class has some buff they can apply to themselves, be it food buffs, spell buffs, or shouts. The key here is that you can find a minute or two to always buff at least yourself, if not others. Although, it might not always be possible to buff others as you're going along - and that's okay with most raid leaders for trash pulls.