damn, gift of bertox is one of the few I still need...
Any rate.
There are a number of things that will affect your dps:
AA Spec
Cast Order
Gear
Group Setup
Raid Setup
Group Competancy
Raid Competancy
This is in order of your control from top to bottom.
AA SPEC
First off make sure that your AA spec is in line with what you want to do... being as we are warlocks we are concerned with two things:
DPS
DEAGGRO
There are a lot of warlocks that will completely ignore deaggro and leave that up to group setup and raid setup to control that fate... and that's what I would suggest for you.
Most will suggest the basic (non-complete) aa setup for sorc tree of:
STR 4448
AGI 44481
WIS 44481
note this is not complete... you need 2 points in each (agi/wis) line in order to get the final ability and after that you have a bonus point to put anywhere u want.
For Warlock tree I would recommend Hastenings, Prop, Explosives... if you want further detail on that, i'll post again.
CAST ORDER
You can find cast order info in the warlock channels. Not gonna go into that in this post.
GEAR
The best gear in the game is not necessarily gear that comes from the hardest raid zones... for rok this is a very sad truth.
Go for gear that gives you boosts in spell crit, cast speed, reuse speed, +spell damage, +spell dmg %, and procs that boost any of these or do pure dmg... (if I missed anything, let me know).
There are places in warlock forum where u can look for gear advice:
Here for example.
GROUP SETUP
This you can't control as much other than bugging your raid leader to give u certain things... to be as simple as possible you will want a troub at all times. If you cannot get ahold of a troub, see if u can get an illu so that you can have Time Compression... wiz is also good in your group for velium gift.
There is a lot more that goes into Group Setup... and I don't want this post to take forever so i'll leave my suggestions at that.
RAID SETUP
Strong tank groups mean you can burn your ass off w/o concern.
Assassin in raid means ur poison spells do more dmg
Brigand in raid means everything does more dmg
Troub in raid means you can get Jesters Cap from time to time
Shadow Knight in raid means your spells do more dmg
Monk in raid means you cast faster
Bruiser in raid means your deaggros are more effective
Coercer in raid means you can get extra deaggro
Illusionist in raid means you can get bonus dmg proc
remind me if i'm forgetting anything on the fly.
As far as player competency goes... your guild should be using all their group temp buffs at the best times possible. Bard should be smart enough to spec fast cast and dktm (if not... shoot them)
Raid Competency deals with making sure people use all their important debuffs and that tanks can hold against strong burns.
Your dps in a raid will almost always be your highest dps and it hinders on everyone doing the right things and the raid being built correctly. Which is why people say 8-10% raid dps is fine for a warlock... it's based on what everything is doing.
What you can do to improve obviously is