My graphic design abilities varied from book to book. I found it very difficult after the first few years to keep coming up with new dustjacket designs. I think my worst are those for the Kurtz book and Magie Duvivier. Both excellent books, but ill-served by my covers.
Interestingly, when Jamy Swiss reviewed my title Folding Money Fooling in Genii, he loved the book, but hated the dustjacket, which is a beautiful piece of art by Earle Oakes of Bob Neale emerging from the center of a dollar bill holding a piece of Origami.
Everyone's taste is different.