See our Fab Lab specific tutorial at:
https://docs.google.com/document/d/1Yck6-zOFX5B75dlv1EvKawbjuQrYNIP15_hh479P71U/edit
Recommended Raster and Vector Settings (50 watt)
Damien Hernandez has constructed a cahedral out of gold colored matboard. Here are some pictures of his laser cut sanctuary.