That's it..set up, aquascape, and don't forget that you'll now have to do something different that FW tanks don't need....topoff with pure water. So, s.g. checks now become routine..until you know how your tank evaporates water.
BTW...just to always keep things interesting, my setup was done all at once and in the same tank. SW was mixed first (after a week of testing the tank for leaks, heat, pump operation, etc). I took a 1/3rd out....placed my first layer of LR straight on the glass bottom, then added a layer of my LR base, filled in with sand, then did the rest of my aquascaping. Made it easier getting every thing in at once. You can always readjust your aquascaping after. Why did I do this? I had read several texts that suggested that doing this will reduce blind spots underneath the rock, and, if you have some burrowers, this my prevent the aquascape from shifting. FWIW. SH