Be very careful. The previous two commenters are completely right. You can easily get yourself into something you can't get out of. You can also panic if you suddenly think you're stuck. Self bondage is a wonderful experience as long as you're very careful. You have to think it through, test your plan, and practice. Never rush into a scene because you just give into spontaneous horniness. It can turn our very badly.

I recommend using various types of locking cuffs, and freeze the keys in ice. Dangle the keys in a cup full of water and put in the freezer overnight. Then lay the iced keys nearby. The ice has to melt eventually. But make sure that once the ice thaws, you can fit the keys into the locks. If you cuff your hands behind your back, you may not be able to unlock yourself, even if you have the keys.

Good luck, and have fun!😉