It's not something you can do with anyone. There has to be a strong level of trust between participants. When done properly it can be an incredible "high" and has even produced some mind-blowing orgasms. However, done improperly can give headechs, brusing, blackouts (okay, that was fun the one time) and in extreme cases; death. I don't recommend plastic bags over the head (that is a bit much for me) but being strangled is my method of choice.
It is also something accomplished at a slow pace. The participants both need to really communicate with one another before, during and after sex to ensure that all is safe. Having "saftey" words and/or signals are also a very smart idea. Like if things are going too far or there is a problem, saying "lemonaide" or tapping three times on the top of the head would be the signal for stopping.
Handcuffs, leather restraints. hot wax, knives, corsets, ropes, gags and blindfolds. These are a few of my favorite things.
