I'll start. In addition to telling him all of my hard limits and soft limits, I also told him of a minor medical problem that I have and the few things that he could possiby do that would trigger it. I made sure that he knew I am claustriphobic, and what portion of my face can be covered before I pretty much freak.

Hardlimits are one thing. They pretty much center around playing. But when I find a Dom worth submitting to I do not limit it to the bedroom. I submit to him in all things. Which means that negotiations went farther than just within the limits of play time. I made sure that he understood that I have a lot of self respect. That I am honest, sometimes to a fault, and that I will never be willing to do anything that will hurt another person, be it physically or emotionally. I let him know what the most important things in my life are. That while, yes, he could force me to give them up, don't expect me to be the same happy person afterward.

I know I am probably forgetting a lot of stuff, but this is what's coming to mind right now.