Hi Nate, You mind if i give you some ideas?! I would actualy create a sort of valley with the sand, coming upfront (from left to right). Not like you have it now, kind of high in front, near the glass. Besides that, you could play with the rocks and put them like i'll show you in the modified photo below. For planting, some Eleocharis sp. (mini) i think would be a good choice for foreground. Going deeper in the "woods", some Microsorum species and Anubias would also do fine. Also maybe some stem plants in the background, like Ludwigia arcuata/brevipes, Rotala species or Heteranthera Zosterifolia.