You can do it however you want to do it. My tactic is always to book a room I'm ok with paying rack rate for in case they don't do discounts, or don't release good discounts, for the resort that I really want. Like right now I have a little mermaid room booked but hoping for BWI, I refuse to pay the current price for BWI rooms so I'm just holding on to the value room just in case because I can stomach that price. If you're ok with paying rack rate for the room you really want then book it knowing that there may not be discounts for that room/room category, wait to book anything, or do what I did. It really is personal preference on how you approach it.