Good advice from dawgdude... but if, like I did, you are putting tank 2 in the same spot as tank 1, some of it won't work. In that case what I've learned is:
Set up QT for all livestock
Have more water/rock holding vessels than you think you need
Have more new water made up than you think you need
Allow twice as much time as you think you need
A large HOB filter or two is excellent for temporary use after you cloud the water from the substrate
An extra heater is nice to get things warm faster
(the last two are directly related to the one about time!)
As stated, use new sand (but clean it well ahead of time)
Have a helper lined up
I wish I'd thought of all those before I did the 13 hour tank swap...