If I started over today, here's some valuable tips I'd live by while adding all the livestock:
It's 100% about quarantine!
1. Start 2 tanks at the same time! One for the Display Tank (DT) and one for a Quarantine Tank (QT). I would add sand and plastic decorations to the QT, so the fish have somewhere to hide and you have something to look at for a few months other than a blank tank with fish. I wouldn't add rocks, as they do make it a little more difficult to keep the copper level steady for quarantine (I've done it though, and it's not really difficult. It just take more monitoring of the levels).
Pro tip: Add a few extra rocks to the DT tank for later.
After both tanks have cycled (If you actually cycle the QT, you don't have to do all those crazy water changes):
2A. Add whatever hermit crabs, decorative crabs, snails, shrimp that you want to the DT. Leave it this way (without fish) for 3 months.
2B. Roughly half way through the above 3 month period, start quarantine in the QT on your first set of fish (2-3 max), using Copper Power for 30 days then 2 rounds of Prazi Pro. This step may have to be repeated multiple times, until you get all the fish you want in the DT.
3. Move the first set of QT fish to the DT and start a new set of fish in QT if needed.
After you have all the fish you want in the DT.
4A. Tear down the QT tank and throw away any sand/rocks that were in there. You can also store it in a bucket if you ever need it again, but once in copper... you can't use that sand/rock near snails or corals.
4B. Wash the QT tank, heater, plastic decorations, filter, etc with hot water, then bleach, then white vinegar. Then do it again!
5A. Set the QT tank up again. This time add a frag rack that you built out of that cheap light fixture grate from Lowes/Home Depot.
5B. Add that rock from the "Pro Tip" to this QT tank.
5C. Add whatever corals you want to this new QT set-up. You can add shrimp, hermit crabs, snails if you want.
5D. Let the new corals, hermits, shrimp etc live in this tank for 3 months, without adding anything else.
5E. NO FISH in this tank. You want a fishless environment.
6. Move the first set of corals to the DT and start another round of corals in the QT if you want... or just keep it going as a frag tank.
This would give you a REALLY good chance of avoiding disease, pest, or plagues that you don't want in a DT.
My experience:
I had the entire tank almost how I wanted it, with only that last fish that I wanted to add. The pièce de résistance!!!
When I added that fish, it was great for a week... then the spots appeared. One by one every fish died. I've been a believer in a good QT program ever since.