Above are my favourite cover mockups (from about 6) for The Ulysses Quicksilver Omnibus, collecting together the first 3 books in the Pax Britannia series by Jon Green. As you can see from the 'final' cover and spine below I ended up combining the 2, as they both seemed too good to waste! I think Jon Green initially suggested having Britannia on the cover, which I liked the idea of.
Below are some of my rejected roughs. You can see the evolution of the ideas to the final version. I tend to tie myself in knots doing slightly too many similar ideas, but these are the main different ones. In fact I'd totally forgotten about number 2... I really like it! Why didnt I do that one? Arg!