It’s all very well to know that failure can be useful to you, but it’s also important to know how to make use of the information you get from it. The first step will be to examine what you did and what happened. Go into more detail than just the mundane ‘it didn’t work’. Layout everything you know about the choices you made, the environment you were working in, anybody else who was involved and any outside forces that were at play.
There are different types of failure, and it’s important to hone in on what exactly was going on this time. Was the failure a result of human error? Failure of a complex system? A missed opportunity perhaps? Lack of ability? Lack of investment, whether of time, money, or other resources?
The answer may well be more than one thing, and unpicking the root cause of a failure may not seem like a fun way to spend your time! But once you’ve honed in on one or more things that you know you can improve on for next time, you’ll be so much better off.