I've never been very good at drawing.  If you look at my design portfolio (see below) you'll see I was a model builder--not an artist who created beautiful renderings. 

But while working on a book project that deals with personal finance and money management, I was thinking about illustrating with diagrams and stuff; I created some little doodles. These two stood out. Later, I juxtaposed them and added the captions.

The diagram idea didn't make it into the book, but this image appears and actually served as a kind of touchstone for the writing.

It's simple and profoundly unartistic, but this image actually captures a significant essence of the book.