I haven't had years of SM experience with dance, but the few times I have, I've learned a lot!
The choreographer can be your biggest help (and your worst nightmare)...get to know him/her and how he/she plans to work. Get this person's trust and support right off the bat.
Rehearsals are your chance to "figure out" the situation...general attitudes, who and what you'll need to pay attention to, who you'll need to keep an ASM on, etc...!
ADAPT to the situation...not compromise your integrity as an SM...do your job, but be flexible. I was never a dancer, but I know that opera singers work differently than actors than ballet dancers than whoever else. No one wants to be treated like a statistic, especially artists. Treat them as professionals in THEIR field, and be sensitive to their worlds.
I always set my expectations ASAP, depending on what part of the process I'm in. Stay ahead of the game if you can. For example, don't wait until they've had an onstage rehearsal to tell them they can't leave their legwarmers all over the place. Before their first onstage rehearsal, I always tell the choreographer that I will want time with them before he/she starts. I make a point to gather them in one place as they arrive, and go over the details...I always start by saying that I am most concerned about their safety. If they see/feel things like slippery places, tell stage management as soon as possible. Then I tell them how they can help make the production go smoothly...this is where I tell them not to leave their stuff onstage. I try my best to let them know that they're safe with me around, but that they have to do their part and help...that has usually worked for me in terms of getting them to trust me and the work I do, and not antagonize them. I don't usually have to talk to principals...as someone else here said, sometimes, they're a little different. Depends on your situation.
I once called a Phillip Glass piece...basically, I had to throw out most of how I knew to call a show out the window. It was nerve-wracking at first. I thought I was going to vomit the first day. In retrospect, it was REALLY FUN to LET GO. Be flexible!
I also like to call artists by name, even if there are 150 of them. That is the fastest way to get artists to break down their wall. It's a lot of effort, but it works for me.
My advice: use what works best for this specific production. Have your "tools" ready, but only use the ones you need for this project.
Good Luck!