id add more substrate, then give it some slopes and angles. deeper in the back. put big plants in back small in front. maybe lay those pieces of wood rather them them looking like they are growing out of the sand. play with it a little and look at a bunch of pictures, it will get there, just takes time. Hope this helps a little, Im really new to planted tanks to and am always looking for more input. good luck, ill try and keep an eye on your progress!