We usually make most of our reservations for next winter in Florida while we're here this winter. We favor state and national parks, and getting in early on the 11 month state park reservation windows gives us the best chance of getting the sites and parks we prefer for the time frame we want. The national parks have shorter windows, but we hit them as soon as they open as well. For this winter, we were late reserving due to some medical questions that determined if we were coming at all, but we did still manage to fill out a near 4 month schedule by choosing central and northern Florida locations plus a few weeks in a southern Georgia state park. During the rest of the year we also make far ahead reservations at places like upstate NY state parks for popular holidays like Memorial Day, the July 4th, and Labor Day. In between, we're a lot more flexible, often making last minute decisions or changes. For those, we might only make reservations a day or two ahead, or not at all in areas where there are several park choices.