Well, fast enough anyway. Will premise this by stating have fun and be flexible with the G'MIC sliders. Anyway, first, you need to pick a target. Using a Tithonia extract (flattened on white) for this one.
Now run G'MIC's Stenci preset with the settings below:
What you have so far:
Blend using this texture for the following:
Flatten and run with the settings below:
Result (click on image for higher resolution):
Also, click here for another example which started it all.
Also, below a varient by replaceing the target with a blended result of G'MIC's Stain Glass preset (background white still) before going through the procedure. Again, experiment for yourself. :)