How many make park reservations vs find as you go.

We tend to make "destination" reservations and wing it from there. We definitely are not destination campers, rather just bop about as the wind blows. Example, our recent trip to St. Augustine, FL; we wanted to see the area and spend some time there. So we made reservations. Knew when we had to arrive and depart. To and fro were what ever we saw that was interesting and available.