Tony Gonzalez recommends Vishen Lakhiani's 6 Phase Meditation in the New York Times.

I’ve actually been meditating for almost 15 years. When I played, it had to do with visualization of the game. Now I do it for my emotional state. I’ve used apps and guided meditations, but when I started, it wasn’t trendy and it wasn’t easy to find all this material that’s so accessible now.
There’s a guy on YouTube that does guided meditations called Vishen Lahiani.