I started with my iPad and made a screenshot of my chosen picture: a bear from the side. Then I started tracing it on a sheet of paper, placed on top of my iPad. The polygons didn’t go as I intended and so after uploading it to Illustrator and starting making the paths I aborted it. The Illustrator-part of this endeavour is quite tedious. And it’s easier to see it through when you believe in something from the start, then when you hope it will look better when colored.
So I started a second bear pic, this time one roaring into the camera. Here I didn’t try to print it (colored ink is empty/expensive) but went via overlay method in Illustrator.