make a sketch just using the sktchy tool.
Rules, refs allowed, just one ref allowed but straight copies not allowed.
You must use at least 80 percent sketchy tool.
Here is a link to a sketch that has a tutorial about sketchy tool in the wips.http://app.sketchclub.com/sketch/10851852
You can use as many colors as you want.
The aim is that you use sketchy tool as a sketchy tool, so the result should be different from any other sketch you do. I say this because can make any tool look like any other tool by tweaking the settings. This is not a rule you can enforce though so it would be a recommendation.