Bondage is one of the more potentially risky areas of kinky play if you're not careful, so I'm going to cover the main safety aspects. There are some not-so-obvious traps for the unwary, and even experts can get caught out, so don't get complacent.
It goes without saying that you should only engage in bondage with somebody that you trust and in a consensual situation. Be very clear about what the rules are to be before you start. When you're naked and tied-up is not the time to discover you have mis-matched expectations.
Japanese bondage in its original form was designed not only to restrain but also for punishment and torture, some of it potentially lethal, so never underestimate the effects of even relatively simple bondage, especially over time, or how quickly things can go wrong. Thankfully most problems can be avoided by common-sense and a little care.