I struggled finding many what I call proper planted cubes when I was looking for my nano cube the only real pointers I can give is search google images with searches like
High tech planted cube
Planted cube aquarium
And as many other variations you can think of :)
Ive spent all day playing around with my mini landscape rock for me dennerle 30l cube, ive made a wooden box (with no front) the same dimensions as my tank so I dont scratch or smash the tank but im having a real problem trying to create anything that looks good, I kind of know what im trying...