Back lighting would add a lot! It goes especially well with clear sand and an open scape like you have.
I think you have too much clear sand. It shouldn't go so far to the back, except a path that goes all the way to the back glass. And less sand will mean some more plants.
Aquascaping theory says you should have a focal point at about 2/3 the way on one side. The only thing I can think for that is to replace the driftwood on the left with a bigger/higher piece with the tip that arrives in that focal point sweet spot, and put moss on it.