It's a look that's not as popular today, but I've always been partial to a ricordea garden eventually covering the sand. This was usually done by placing a ton of rubble of the substate and letting them grow all over each other. In fact, one of the craziest tanks I'ver ever seen had a wall to wall ricordea garden on the sand and GSP completely covering the back wall. If I'm remembering correctly, he had amazing SPS near the top of the tank, LPS near the middle, then zoas filling in all the blanks. I looked around for an old pic on RC since it was a TOTM at one point, but this was probably 10-12 years ago.