This is something I showed @QueenOfHearts. Not sure if I learned this from somewhere. Im sure you guys have used or know of something similar, but hell with it, I know will benefit someone.
Sit in a comfortable position with your spine straight as you can. Close your eyes and just breathe. Focus on your breathing. In through your nose and out through your mouth. Get lost in this rhythm.
Once you feel spaced out, picture a white (or whatever colour you want, I just go with white) light surrounding you. Breathe it in through your nose. When you exhale, picture all the negativity and days shit coming out of your mouth as a black (or again, whatever colour suits you) fog. Repeat this until you are satisfied.
(Feel free to add your cleansing meditations )