Tyler,get youself a couple 18" long pieces of Tonga branch LR.Tonga branch is great for elevating your aquascape up off of the sandbed.For a 3' long tank,I'd try to have no more than 3-4 points of contact(base of the aquascape) in the sandbed.Try to leave as much space between the glass and aquascape as possible.AS Repto mentioned,rockpiles are a bad idea.I prefer to start the base of the aquascape in the back half of the tank and leaving alot of sandbed open in the middle.Then toward the edges,I'll bring the scape up closer to the front.This gives the illusion of a wider tank(more depth of field).It also will be a great place for solitary sandbed corals.
I guess when I said "pile rocks" I was being to general, I don't literally mean "pile", it was just a term for a group of rocks, usually with just one rock actually on the sand. But yes Dave, I like the idea of an open center or a "horseshoe" effect. I am not real keen on the idea of PVC frames as I don't really know what I am doing and I would absolutly loose my mind if I could see the PVC from any angle. However, I hadn't much considered tonga branch, and I might have to consider that for the base part of the structure. What do you think of mixed varieties of LR? I have already commited myself to 50# of LR which I believe is just your typical Fiji or Marshal Island shapes. I have never really liked the thought of mixing varieties but it could look good...