Step 1: Prepare design for laser cutting
I used inkscape, which is a free drawing program that's easy to learn. I started by grabbing the template from ponoko's site, started drawing a rough sketch of what I wanted the final product to look like.
After getting an arch I was happy with, I copied it and then used inkscape's boolean tools to remove rectangles where the crossbars will go.
For making symmetrical pieces, you can draw half the piece, then use inkscape's clone tool. This way, any changes you make to the original will apply to the clone.
A couple ponoko tricks:
* You're charged by the time the laser spends, so you can save money by putting things close together, and combine lines when possible.
* Cutting a material that is twice as thick costs four times as much, so whenever possible use the thin stuff.
* Plan ahead. Getting stuff from ponoko takes at least 3 weeks.
Step 2: Assemble the frame
When glueing, make sure that the glue does drip anywhere. If it does, wipe it off and then lightly sand the area to remove any traces of the glue. The traces of glue could mess up the wood stain in a later step, and it's better to be safe here.
In addition to cutting materials, ponoko allows you to engrave your designs. In the second photo, you can see a small logo that I had engraved into the base.