Turn an ordinary air compressor and some play sand into an etching machine.
The air compressor tube needed to be dremeled out to look like this: _--^^--_ This way sand will be pulled into the tube using Bernoulli's principle instead of shoved into using McWain's principle - [Anything that could be cool usually fails and winds up stupid].
I copied some cool logos from DuckDuckGo Image Search and cut them out on a vinyl cutter. After applying the stencil to the outside of some coffee mugs, I turned up the PSI and went to town.
All things considered, these came out exceptionally well and were given away as Christmas gifts. I will be doing more etching projects like these and hopefully get much better over time.