Cap'n: Euhm, what you could do, Add more brushes if you're a fan of it, but if you add those, make sure the colors match. You also could use some C4D's, but not too much.
Blend in more, (45 px soft brush, and erase anything that stands out too much of your render)
Colors,
Text colors.
7/10 overall rating, as Zhell said, they're decent, but pretty basic.