Welcome! :O)
I use psi dart to build domination fast, as it charges quick and has a low animation time. Anytime I try a new dom I look for an equivalent power with those same properties.
My MA IDs:
Fiend Space: 211464
Welcome to the darkly twisted world of Domination. Started my first proper one last thursday, and haven't been able to stop. It's the fastest-leveling toon I've ever touched. 
The ability to control and blast makes it really something even at low levels, and of course there is that lovely orange Domination that really makes the day when it pops up.
Hasten and Stamina are really wonderful tools. I would add Aid Self amongst the nifty stuff from pools - once you've controlled the enemy, you can shrug off the damage they did in case you happen to miss a hold.
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The key to building domination fast is the aility to spam attacks with very short animation times. The Psi Dart machine-gun is notorious for achieving this with one single power although at later levels I found that less useful as I already had a very tight attack chain (with rather short animations) with much higher dps.
That´s why I found respecs very useful for my dominator, much more than for any of my other toons. Depending on your powersets, level and personal preferences you might want to slot some fast animating powers for recharge in the early game and respec later when you have access to more - perhaps equally fast animating - powers with higher dps.
However, have fun with your dominator. They are much better than one would think after reading the forums. 
If it has eyes, you can blind it, if it has blood, you can make it bleed, if it has a mouth, you can make it scream.
Usually play heroes, haven't gotten much into the villain side of things, partly because comp isn't quite up to it, partly because I haven't found a char to settle into. Tried Corruptor which on paper seemed like a Defender with more damage, but because of thermal secondary felt like too much of a buffbot like my kinetic; tried an MM and while I could see that I would enjoy it, I find the AI a bit irritating. Tried a Stalker but the stealth thing doesn't really turn me on.
Finally tried Dominator. Yess! This is the villainous archetype for me!!! Every time those orange "Domination!"s fly up, I feel fulfilled.
Amusingly, I also feel more like roleplaying this char than any other - kind of a cheesy villainous role but fun (a bit like a Vincent Price type).
Also starting to "get" villain teaming. It's all about momentum and building up a head of steam, pretty much defined by the Brute's role. I think the idea is that you are supposed to feel a sense of ownage as a team, rather than beating a challenge you've really created mass havok and mayhem.
All in all, good clean fun!
P.S. Any tips for having Domination come on as much as villainly possible would be greatly appreciated! I've realised Hasten and Stamina are going to be a must, obviously, but any other ideas. Is it worth having recharges in the faster powers, maybe get that single target immob just so it can be spammed to build Dom, etc.?