We all respect each other's needs. This goes beyond the bedroom. If you're just getting into being poly just for the sex you're not doing it right (in my opinion).
Keep everybody in the loop. This doesn't mean sharing things are meant to be secrets. It's more like... I can't describe it well. Let me use a recent example. Chance recently lost a friend to suicide. I had him staying at my place for about a week so I could keep him safe. We had very deep, personal conversations about it.
Josh wanted to have a quickie with me during this time. I told him I was with Chance and he needed me more, because he lost a friend to suicide. I didn't go into fine details, but I gave Josh enough info to help him understand. Josh was disappointed, but respected Chance's needs and my own.
Also: We all know about each other. Everybody knows about the others, even though we're never all in a room together. I keep each partner up to date on the others' lives (without divulging anything too personal). I don't make it a point to be anal about telling them all a thousand details, but I might tell the others if one of them got a job or went on a trip or got sick or something. Each of them regularly commonly asks about how life is going for the others, especially if one of my partners is suffering.
Sometimes I go to one of them for info to give another one in their areas of expertise Pat is a psychic when it comes to cars, Chance has some medical knowledge, and Josh is a wizard with computers and electronics. So if Josh's car is acting funny, I ask Pat and I write his suggestions in a text to Josh.
I hope I haven't droned on too long here... I could probably come up with more, but I've already given you a wall of text to read lol
Ask me if you want to know more! I have known I'm poly for less than a year, but I've been practicing polyamory for almost 20 years. I'm an open, blunt, straightforward person. I used to write adult fiction. You can't freak me out lol No topic is off limits!