My wife and I were remodeling our house and decided upon putting in a custom bar top. We thought it’d be fun to burn a Lichtenberg fractal pattern into the wood.
The first thing I did was measure out the size of the required board and make the bartop out of 3/4″ plywood. I had to stitch together two pieces because I was using up some scrap. This was really easy to CAD up and cut out on my company’s CNC Router. 
Here’s a quick test fit in its final location.
After some testing we realized that we’d get the desired effect from thinner material. So we cut a piece of 1/8″ luon for the bar top surface (once again using the CNC router). We applied salt water to the surface and used some brad nails as the electrical probes. We used a neon sign transformer for our high voltage supply. It takes a little bit of time to burn the wood, but it’s fun to move the probes around to get the desired effect. You can also steer the pattern a little bit with judicious usage of salt water.
We followed it up with some thick bartop epoxy. There’s an art to applying the epoxy bubble free and making sure not to have any “soft spots” that never harden. But, we managed to get a pretty decent result.
The only thing left to do is to install the unit and support the dangling edge with some custom scroll work. We’re thrilled with how it all turned out. If you’re interested in trying it yourself, I suggest practicing before you commit to the final piece. There are a few different techniques to get a variety of effects, so trial and error is the key. Have fun!