Pretty much echoing what the two gentlemen above said plus throwing in a surprisingly quick paint over.
In regards to shadows, if you want something really poppin', nothing works better than the simple use of a complementary of your base color. Here the base color is red, so I threw down some green shadows on a separate layer with the opacity set to 65%. Also added in the drop shadow Raul mentioned, a few extra highlights with a 1 pixel paintbrush and some simple B&W gradients with various layer settings, a curves adjustment layer and shazam!
So much you can do in Photoshop to make an image interesting without really doing anything, so have a play around. :]