First and foremost, think about what made you decide, out of all the places in the world, to choose this particular destination. Whatever it is—the beach, the rides, the mountain, the galleries, the food—obviously appeals to you. If it didn't, you wouldn't be going there. That site or activity (or inactivity) is one of the things you want to photograph. But there are probably many other interesting aspects of the place you may not be aware of. That's where research comes in.
It was in 2006 when I traveled to the sacred city of Varanasi for the third or fourth time; this time in search of real sadhus rather than those I encountered on the ghats of the river Ganges. The more photogenically flamboyant of those would "earn" a few rupees from tourists and photographers who sought to augment their inventory of exotic portraits of these characters; perhaps paying them a tidy sum if they agreed to be photographed in a rowing boat or next to a temple.