It's an art form that is best left alone unless you know what you're doing.
When you choke her, please do not try to freaking kill her! Choking is about a dominant hold or should I say an authoritative grasp. It is a form of bondage. Do not, I repeat, DO NOT cut off her air supply!
Do NOT do it if you do not know what you're doing. Some of you get too excited during sex such that you end up losing your mind and not really understand what you're doing.
Just leave it.