I think we've done a little bit of everything at one time or another.
When we had the 550 here at school we used a glued PVC frame, zip ties, and coraline colored marco cement mix.
We have a rock pile in the office that I used long masonry bits to drill for acrylic rods. This was really hard for the more dense rock pieces.
We have also used the plastic melting pellets that you can form similar to cement. Those worked well but is white until it gets overgrown with reef goodies.
We've used the 2 part epoxy putty too, but it isn't cheap and you need a lot for a big build.
At home we let gravity handle it which is not mine nor Jodi's favorite method as we have had some rocks shift when adding or removing corals. I think we would both like to get in there with some glue or epoxy to make it more stable. I keep hoping the corals will naturally glue the rocks together.
I think what I would prefer is if I am using dry rock I would use either PVC or acrylic rods with additional support from a reef safe cement mix. Zip ties are great, but take a while to get covered and hidden if you don't cover them with cement. The plastic pellets weren't bad, but we were working with wet rock and there wasn't any cure times on that.