I was taught, and now teach, that you select the attitude for the airspeed you want, and then use as much power as is required to maintain your height. I believe that this is the way everyone is generally taught, in the R22 at least...though I can't be sure of that.
OTOH, when flying the B206, in which I have only a very few hours, I was basically told to leave the collective alone, since for some reason which I never quite grasped it wasn't a good idea to keep adjusting it.
And when I did a couple of hours in the MI-8 in Russia, I seem to remember the instructions were different yet again, due to the difficulty of constantly trimming the cyclic in such a heavy helicopter...but I was doing it all through an interpreter whose English wasn't great, so I'm not sure I understood all of what I was told anyway.
So I'm wondering...does it maybe depend on the type of helicopter?