Step 1: Make a Template, Then Engrave
You only get one shot at this for alignment.
The first thing that I did was to measure the bottom of the bowl. Next, I measured the outside diameter of the bowl. I took a piece of cardboard and cut a hole using the laser so that I would know where I would be able to position the bowl for the final engraving.
Next, I made another donut shape with the engraved message. That was also cut out of the cardboard.
When I made sure that everything was correct, I put the bowl in the laser, and since the first hole was the registration point, the message on the bowl engraved perfectly!
I did this a while ago, but I am just now getting around to posting it as in instructable.
I made it at Tech Shop.