There's a few typical "layouts" that most people use. In my 75 reef I have built up both back corners and let it drop a little in the middle. Sort of a concave boat shape. Some people put one side higher than the other, or make sort of an archipelago shape with the ends curling towards the front of the tank. Some even make two spectate rockscapes and leave the middle sandy.
125 malawi cichlid, 110 Discus, 75 reef, 30 reef, 27 reef, 4 planted