Sometimes I will, other times I won't. It depends on the color I'm using and how it reacts with the surrounding colors. For the dude's pattern, the red areas are combination of light and dark reds, whereas for the rest of his body I used light and dark yellowish browns. I hope that answers your question.
The Spacing is at 5%. I keep Opacity at 100% all the time (I rarely ever use Opacity 'cause I don't like the way it handles). The only thing I change is the Flow. I use keyboard shortcuts to quickly set the percentage. I've never seen other artists use a brush with these settings. It's just what works best for me.