The cover for The Sea Witch and The Box were designed by someone that is extremely talented and very artistic. You can contact her here:
Tammie has a wonderful eye for how a book cover should go together. If you are putting together a novel you should talk to her about designing yours.
The covers for my non-fiction titles I designed. I do pretty good with those as they are rather simple to say the least. Probably my best was the cover for Growing Things.