Shapeways objects, especially from our Objet printer, look pretty good after printing - they are high resolution and have smooth surfaces. Sometimes you may want to add some extra finishing though - maybe to add some extra color or to further improve the surface texture.
These three articles describe in detail how you can paint, dye or polish your objects. The techniques are all pretty straightforward and require only a little investment (mainly paint and sandpaper - you probably already have that).
The polishing may be tricky if you have very detailed objects - I'm going to try it our on my monkeys one of these days. If you have applied a finishing to your designs, let us know how it went and we'll share the result.