Aquascaping is a personal preference. I have a couple of pointers that may be useful though. Stay away from the sides of the tank and the front, this will make it easier to clean witha magnet cleaner. Try to make several caves and ledges, the ledges serve as a place to place corals and the caves make hideouts for fish. You will probably reaquascape to a point almost every time you add something to the tank, so don't get stressed if you don't like it, just change what doesn't look right.