From 43 Folders:

[Chuck] Close talks about evolving his method of working to overcome his own personality.

“I’m a nervous wreck. I’m a slob. I have no patience. And I’m rather lazy. All those things would seem to guarantee that I would not make work like I make. But I didn’t want to just go with my nature.”

So instead of painting overwrought, expressive things when the mood struck, he committed to making his epic, close-up portraits by breaking the work into tiny pieces and hewing to a grid. Not only did the grid make technical sense, it forced a lifehack on Close that would help him deal with his own tendencies. It helped get the work done…

Link.