Some years back, I put up a contest here for a cover for the third edition of The Machinery of Freedom, and ended up with what I think is the best cover I've ever had. I am now just about to self-publish another book, Legal Systems Very Different from Ours, and it too needs a cover. The central idea of the book is that all human societies face about the same problems, they solve them in an interesting variety of different ways and they are all grownups, so all their solutions deserve to be taken seriously. I am not trying to find the best legal system, simply to understand a lot of real world legal systems and see what can be learned from them, including the problems raised by the different solutions and how they might be dealt with.
Part of the reason getting a cover that way worked last time was that there were a lot of readers of my blog who were familiar with the book. That will be less true this time. A late draft is webbed, however, for anyone curious.
My only cover idea so far is the title plus the names of the different legal systems scattered somehow over the page; this is an example of how that might be done. But I have no expertise in graphic arts, so was hoping that one of my readers could offer either a better version of that idea or a better idea.
The prize last time it was a signed copy of each of my books. I would be happy to do that again—or negotiate other terms.