Once the migrating birds are through and it's only the resident birds it's mostly a matter of visiting the same place often enough to figure out their habits. Most Kingfishers fly along the edge of the water (either a bay or stream) in a pattern. They often land in the exact same perches, as they prefer dead wood extending out over the water. Once you've identified a perch (usually by seeing it flying away from you from that perch several times over a few visits!) you can "stake out" that perch and wait for the bird to come to you.
Soon, if not already, they will also be feeding their families. That means they will come back and land near-ish their bank hole to check for danger before flying in to the nest to feed the youngsters. Again, they often land in the same perches with good visibility while looking for predators.
Because they call while flying it's actually a bit easier to figure out where they are than with some birds. You can hear the calls coming around the bay, for instance, before they arrive.
Good luck!
