Originally Posted by Ehman

Quick note: You might want to upgrade the enchant on your bracers to +30 spellpower and there is a slight DPS advantage to the +50 Spellpower +20 Spirit threads for leggings.

Regarding your DPS in the heroic: It will almost always be lower than on a raid boss, simply because things die too fast for you to even get through a whole sequence - generally. I don't bother with a curse in Heroics, save on the bosses. With the people I group with in heroics, if I get through a whole backlash proc on one mob, I'm surprised --- that means I'm always doing less damage on non-bosses than I would like.

On Hit Rating: Depending on your normal weapon choice (I doubt it is the Argent Lance currently held), you are under Hit Cap for your spec on Raid Bosses unless you always have a shadow priest or druid with improved faerie fire with you (entirely possible, I wanted to point it out just in case).

On Rotation: Ultimo's suggestion is one of the standard openers. I tend to use CoE, Immolate, Conflagrate, Chaos Bolt, Incinerate x3, Conflagrate, Immolate, Chaos Bolt, Incinerate. Yes, I lose about a quarter to half a second waiting on the Conflagrate at the beginning; but, I usually have one or two 0/41/30 spec warlocks with me casting Immolate as their first or second spell, so in a Raid I often don't have any delay. (My job tends to be blow-up the adds quick.)

I still like practicing rotations on Dr. Boom out in Netherstorm, since he has enough health to last as long as a typical 10-man Raid boss (lacking all of the raid debuffs of course). That gives you enough time to practice a rotation and get a feel for it with 'random' adds being the flayer that walks up to you in the middle of it (usually).

Regarding gear: Your Haste Rating is very low right now, making it hard to get off lots of extra incinerate spam. Changing your overall gear based on that might not be the best idea, but even for a Destruction Warlock, Haste means more overall spells cast. One of the reasons you aren't seeing the wondrous effects of your 20%+ Crit Rating is a lot of things (in groups) are probably dying before you get your third cast off (as 0/41/30) and even with Conflagrate, you probably aren't making it through an entire cast sequence of Backlash before things die and that makes your DPS look low. An ideal fight for a warlock casting Curse of Doom lasts 60 seconds with the CoD ticking to kill the mob (or a second longer with the spell that is currently casting finishing the mob).

Hopefully this will help.