I picture the what's bothering me, what's preventing me from being at peace, all of it.
Then I imagine a door, I open it, put what's bothering me behind and close the door.
If it's still bothering me, I picture a thicker, sturdier door, and close that one.
If that's not enough, I picture yet another stronger door, chain it, build a wall, seal everything in a vault, cover this vault with a wall made of the hardest diamond, and finally put everything on an island in the middle of an endless sea.

Finally, with all the chaos locked far, far away at the back of my mind, I can focus on the positive things. I can be at peace.

I may sound like Yzma from 'The Emperor's New Groove', but it always works.