If you are like myself and have listened to conventional wisdom and you've worked and worked and tried and tried and still haven't fully obtained the fruit of your efforts, then this should be helpful.
The secret to the art of letting go is to simply focus on the areas that you have the power to change.
For example, if you know in your heart that you should be a best selling author don't frustate yourself because the sales aren't coming your way. You can't make anyone buy your book(s) no matter how well you market. What you can do is focus on becoming a better writer while simultaneously putting out a good product from cover to cover and then allow the sales to come your way. That's not to say you don't market but more importantly you focus on giving your best self. If you give of your best self consistently, everything meant for you will come to fruition. This works because more times than not, we can't see the thing God is trying to work out in us, because we are too busy seeking the reward when we should be seeking to be complete.
This is the state I find myself in these days. I'm still focused, still goal oriented, but rather than focus on the reward - which I have no control over - I'm spending my days working to improve those areas in my life that I know require more input. So in effect, I let go of what I can't change and change the things that I've been empowered to.
It sounds simple, but thanks to pride it's not the most obvious path. For what I'm finding is that as you embrace the art of letting go, and you continue to evolve into your better self, you become more capable to recieve the reward you thought you had to work to obtain in the first place.
Be blessed.