Step 1: Trace an image with the pen tool in illustrator
Take a simple photo or sketch, import it into illustrator, and trace it with the pen tool.
My shape involved a bunch of mirrored figures, so I traced one side and then copied and pasted and mirrored it.
Step 2: Copy, Paste, Mirror, Shrink or Enlage, Rotate and Duplicate
Mirror the line and link together the lines with the pen tool.
Add variety to your design by rotating, shrinking or enlarging the shape.
Step 3: Or use Live Trace
You need an image, which you can drag, or copy and paste into Illustrator.
In Illustrator, go to menu Object>Live Trace>Tracing Options.
When the dialog box pops up, check "on" the preview feature.
Slide the threshhold number up and down until you get an image you like.
Keep it simple! The more lines and intricate shapes the laser cutter has to cut, the longer it takes and the more it may cost, if you are paying a laser cutting shop.
Step 4: Finished Design
Shapes should not overlap. If you have experience working with stencils, it's the same type of thing where overlapping shapes will fall apart if cut.