Now I've only read Harry Potter and the Order of the Phoenix and just started Half Blood Prince, so my choices were pretty limited. The edition of Order I've been reading looks like this:
Which, while easier to recreate then the typical American cover, still required something...birdlike...and since the closest thing I have to a bird is a build a bear dog (which looks nothing like a phoenix and everything like a small terrier) this was off the table.
Which brings me to the cover I actually recreated.
I know, I know. It wasn't exactly a difficult task, a book on the cover of the book. But still, it was that or a weird bird dog. I made a "pretend" crappy cover for the book. Since it didn't show up well in this picture, it says:
"Suspicious Potions Book
(try all my fancy new spells!)
Forward by the Half Blood Prince"
Evidently I am not very creative today