If your just hitting your OGCD when ever they proc your playing DRK wrong well not fully wrong but it isn't always the best idea to pop OGCD's just because you can pop them.
TB in coming? ok I'll save Reprisal for it.
Mob needs to be stuned? Someone else do my low blow is on CD.
Tilts in coming, ahhh I've fallen off the edge! If only I had Plunge on CD so I could have lived.
But yeah sometimes you got think more of the skill to fully use it.
Also time your BW and OGCD's. If your Plunge is ready but you 3 seconds left on your Blood weapon then wait till it's ready, pop BW then plunge you'll get extra MP because of that.
Too many people just pop OGCD's just because there ready
But on a side note, post a screen shot of your HUD layout maybe I can help?
eh, I've still got loads of space left on my controller. Could easily fit in another 10 skills.