This was an Eastern Caribbean cruise to Nassau, St. Thomas, and St. Maarten on the Carnival Valor. I went with two friends - all of us are in our mid-twenties. We have previously cruised Carnival together before, and I have also cruised NCL, Royal Caribbean, Princess, and Celebrity.
We flew to Miami a day early on American Airlines from LaGuardia, and it was the most disorganized check-in I've ever seen. If I hadn't sweet talked a guy from the curb-side check in area, I think we would have missed our plane. Things improved once in Miami, we took a cab from the airport to our hotel - the Doubletree in Coconut Grove. It was about a 20 minute ride, and $25. The hotel was very nice and clean, and had one of the best gyms of any hotel in it's class that I've been to!
We got settled then took a cab from the hotel to the South Beach area. Another $25-30. We walked down Lincoln Road and had lunch outdoors at one of the many restaurants on the street. At the end of the road you hit the beach, and while we didn't have our bathing suits, we took a walk down to the water and took some pictures.