I get bored working on the same surface, using the same size or even painting in the same style, day after day, so I often switch things up a bit. One day I might paint something on canvas that is 5 feet tall, and the next day work on a 4" square wood piece. Today I wanted to do another mini canvas, this one sized 4x2". I decide to paint David Bowie's eyes and I love how it turned out.
They seem to follow you from across the room.