I have a feeling you are SoL when it comes to your warlocks if you are using your DoT(s) to get your DPS out of them.
Many of the warlock DoTs put out more DPS at the end of the life cycle than at the front, so any DoT that didn't make it to full life didn't get you full DPS.
they will only shine or out perform others in your team when they are getting all of their DoTs going and it takes time to cast all of them.
They should shine when it comes to a boss fight because with proper applied DoTs and life taps they shouldn't go OOM, and the boss should last long enough for all of the DoTs reach maturity.

for afliction i used to use the longest lasting dot first which I think is siphon life.
Haunt should probably be manually applied because drain life works best with more DoT on the target.
/stopmacro [channeling]
/castsequence reset=target/5 siphon life, curse of X, corruption,unstable, immolate, life tap,drain life, drain life
I suppose you could always go destructo and spam shadow bolts but they have a long casting time :-(

I can have my level 70 warlock out DPS my level 80 shaman in Kara by having him spam seed of corruption
so maybe you should look into the warlock macro for spaming seed of corruption on trash mobs.
someone had a macro that limited the range the /targetenemy works on so that the warlocks were not targeting stuff out of range. I use it on my warlock at times, I'll look it up later.