Step 1: First: Print.
Print this 3D Model: http://www.thingiverse.com/thing:23899/#files
(Thanks to CarryTheWhat for the Model itself)
Step 2: Paint the Deepest First.
I used Acrylpaint.
Step 3: Overpaint the Paint Like 3-5 Times
Be gentle and do it like you would paint over a plate without going under, like you Paint the air over the deeper Places.
(Argh, man. You know what i mean)
Step 4: Adding Lines.
I used a TOOTHPICK to do it.
Use something like that and your finished.
Mine is like 4 Months old know.
Thats why it have a nice used-Touch.