Laser Engraving
From HeatSync Labs Wiki
General guidelines on how to get the best engraving results. Overall, I'm really unqualified to give you help here, but this is where I'll document as I learn.
Clear Acrylic
The trick here is to mirror your engrave. You want to be engraving on the "backside" of the acrylic because it looks better. As a result, you'll need to use the "mirror" when you go to engrave. Create your design as you want to see it, and then just do it in software at the end.
Other Materials
Document some stuff here.