Earlier this year, I wrote a kindle book called How To Improve Concentration Fast: Lost Secrets of Focus, Concentration, and Meditation.
A couple of months ago, I created a video on youtube that walks you through one of the exercises in the book. Take a look:
(watch the Improve Concentration video on YouTube)
Play with the exercise, and if you like it, take a look at the book: Amazon.com/How-Improve-Concentration-Fast-ebook/dp/B007QWXV4W/