Over and Over Again

I've been playing around with the best ways to find complete focus and get in a flow state, which seems to be harder and harder these days.

I can't remember who recommended it (maybe Forrest Walden?) but I started listening to the same song on repeat while I'm working.

The. Same. Song. Over. And. Over.

It sounds terrible at first, but after about a week of doing it, I've found that it is insanely effective. I think it triggers something in your mind that it's time to focus and the lack of changing to other songs keeps you in a great rhythm.

So far, I've done it with a couple songs:
­čÄ╝Neon Future - Steve Aoki
­čÄ╝Experience - Ludovico Einaudi 
­čÄ╝Gold Star Mothers - Hammock
­čÄ╝Freedom/The Execution/Bannockburn - Braveheart Soundtrack

Have you tried this before? If so, what what songs do you recommend?