I built a 30 page "311" fan book. I never advertised having made it, it never got documented in my portfolio. In a tale of "scope gone MAD" I took on a $500 commission in 2012, and then it turned into what should have been a $3k project.
I basically got bullied into never stopping work on it. So, four years later, here's the cover for the unfulfilled "311" fan book I built.
It was actually print-ready... I had started work on the second of FOUR of these, having never collected the initial confirmation fee, before I got the nerve to stand up for myself.
Don't ever work for free based on promises. Work for pay based on being paid.