Make a stencil, and custom spray paint your laptop.
Step 1: Design the template
Bold designs work best. Try to keep all features larger than 0.150 inches.
This one is designed such that you can cut it from one piece of material and then snap in the interior pieces to do different layers. Since you never have to remove the first layer, the subsequent layers are already aligned.
If you are going to laser cut the template, make sure your design is in a vector format. Programs such as Adobe Streamline can turn bitmaps into vectors.