Last year, I painted some cards for Cryptozoic Entertainment's new game Hex: Shards of Fate. I've already posted my favorite of the pieces I created for the game. You can see it here: http://www.jimnelsonart.blogspot.com/2013/09/rocket-ranger.html
For several reasons, I needed to keep my approach a little simpler and less detailed on these cards but Hopefully, I was still able to capture a little magic. The dwarves in the game lean toward the cartoony side (which I liked) and toward gray in color. Consequently, I used muted colors and punctuated them with stronger hues where possible. The images went through some color revisions at the end so the large fellow in green is actually wearing a muted red in the final art. I've posted two versions of one of the cards below so you can see how purples and greens were also shifted to red for the final art.
It's a fun challenge to try and simplify what you're doing while still coming up with something that is (hopefully) an effective image!
You can learn more about Hex at: http://hextcg.com/