Make your room request at the same time you book your original reservation. Room requests with the most seniority have precedence. Five days before arrival is when the actual resort receives the booking from the CRO. Call the resort in the morning 5 days prior to your check-in date to confirm that they have your room request on your file.
I found out about the five-day thing from a helpful cast member at the CRO and they even gave me the WLs direct number to use when the day arrived. The CM at the WL is the one who told me that the oldest requests get first pick.
We used this strategy successfully, we even gave them my top three preferred specific room #s and we actually got one of them. I had found out from different threads on this forum which 5th floor WL rooms with the MK view had bunk beds - and we wanted one of them.
We intentionally did not use this strategy at AKL. We had booked a standard view room and I was hoping for the complementary upgrade to Savanah view, and I didnt want anything to get in the way of that. It worked!!!
Even if you dont get what you request, it will be OK. We have been going to WDW for a long time without knowing these tips, and I havent had a bad room yet.