I am working on this same question. Do make sure that your driftwood/rocks do not cover any soil. If roots can not penetrate your soil you will create H2S pockets. Also anything you can do to have emergent plants is worth the effort. This will bring more carbon onto the tank. I have been considering a dwarf lilly as my lights are close to the water level.
I only have 2 watts per gallon so I have been looking at low light plants.
I only have 2 watts per gallon so I have been looking at low light plants.