Lines.
Lines need to be straight.
Everything needs to be parallel, perpendicular, or in a set radius.
When I see painted stripes on a road that look like the driver was drunk, I get an inch in the middle of my brain that I can't reach with the coat hanger.
The remotes on the coffee table. They have to be side by side, parallel and pointing at the tv. And the coffee table better be parallel to the couch and tv or there will be an episode.
Lines down the back of stockings. Better be perfectly straight and not all wavy or gtfo.
Just few examples.