Welcome to thel atest thing I've thought more about than I really should: Color. I have a tendency to use the default palette of every art program I use, but I'm araid that'll give my art a generic quality, not to mention gaudy since msot of those are usualy set at pure colors. So what I did is gather the colors I use the most and replace the default quality with it. I'm sure this will evolve over time, but for now at least, it gives me a pretty decent sense of how I want the color scheme of my comic to be. A subtle thing, perhaps, but the devil's in the detail.