When I find a way to make something look noticeably better with very little effort. Like, I realized a few months ago that the dirt trails and paths in my backgrounds look weirdly so much better with a few scribbles from a sienna brown fineliner I've got. For whatever reason, it takes the dirt ground from 'okay, that's fine' to 'oh, wow, yeah, that looks like flat soil'. And all it took was 30 seconds with one pen. WIN.