Great start. I love the overall valley type layout. I've always wanted to create something like that, but obviously I have no real skill in aquascaping. The way you did it works pretty well, but I've always seen similar aquascapes with dark type rocks paired with the white sand since I believe it helps define the V-bed better. With that, the rocks would also be a mixture of smaller and larger rocks, spaced apart to form the lines with the intent to make things more natural looking. Not to say that the way you're doing it is wrong, just different from what I've seen.
Once the HC fills in that foreground and the moss rebounces to cover the driftwood, I think it's gonna look pretty neat.
-John N.