If you select all the external edges besides the verticle ones, and then chamfer them (all of this in Edit Mesh) it looks a lot better. I like the creative idea, but they are pretty simple. Get some details in there. I like the shape of the first one, kinda covenant looking.
Just incase that was confusing, here's a little minitut on simple chamfering.
Pic 1, Just a simple little box.
Pic 2, Applying the Edit Mesh Modifier.
Pic 3, Selecting Edge editing.
Pic 4, Selecting all the edges.
Pic 5, Deselecting middle edges. (You probably want to go into the top view and do this too, to get the interior edges (the dashed lines). Just do the same thing, but completely inside the box. )
Pic 6, Chamfering.