One of the best books to read is ‘The Inner Game’ by Tim Gallwey, he explains in great detail about how our conscious mind-Self 1, fights with our natural ability to hit the ball- Self 2. By confusing Self 1 and keeping it busy we can then allow ourselves to play without interference. One of his best drills is the Back-Hit drill, I have taken this and added a few things to help tempo and retain balance, I call it the back, hit, bounce drill, on your take away say b-a-c-k slowly, where ‘b’ is the start of the backswing and ‘k’ is the top of the backswing, then say ‘hit’ when you hit the ball and then hold your finish until the ball bounces and say ‘bounce’. Saying this out loud at an even, calm voice or even in your mind will turn off the interference from Self 1 and allow you to swing tension free.