I was really surprised I didn't get more of a sandstorm to be honest. But I started up the sump and powerheads and it cleared up pretty quick. Also when you add sand after the rock you will have to blow the sand off of it.
It's really up to you on the order you go in. i was feeling kinda lazy so I just dumped it in. LOL Just make sure that the rock is stable first and then you can go from there. Don't forget the bowl trick when adding water... place a bowl or plate on the sandbed and pour the water into that so you dont splash up any sand.