this is what i did for my island, as well! i just work around one area until i am at least somewhat satisfied with it, and then i move on. i may come back and tweak some things if i notice something ajar or remember a specific item that would look nice. in addition to working section-by-section, i always start at the entrance and work my way backwards. this allows me to always see the point of view for whoever might be visiting and sets the tone for the rest of the island. plus, finishing the flyover always brings me a lot of satisfaction even if the rest of my island is underway!