The above poster has some good suggestions- TOPS'L is completely private, you have to be a member or play with a guest- some good players there- last I heard I think Sandestin relaxed their policy to allow outside play with ct fees, but I could be wrong. WaterColor, Seaside, and Rosemary on 30A are available to play with ct. fees, but if you're in Destin, that's a pretty good haul to get out there, especially with possible extra traffic from spring break. You could also consider driving to Fort Walton Beach (west, rather than east to 30A) and hitting at the FWB Municipal Tennis Center. Not nearly as nice as the other places, but a good amount of players and MUCH cheaper.
USPTA Pro, Santa Rosa Beach, FL