Go to the opposite end of the island.

Yes, but you have to go where the tour buses don’t.

On Santorini, that means skipping Oia’s sunset crowds and heading to the southern tip near Akrotiri or the less-visited village of Pyrgos. On Mykonos, skip the windmills at sunset and walk to the far side of Agios Sostis beach. On any island with a famous sunrise/sunspot spot, the best photography is literally the other side of the island at the opposite time of day.

The trick is simple: look at where the cruise ships dock, then go as far away from that port as possible, and shoot at the same time everyone else is shooting the famous spot. You’ll get empty streets, golden light on the backside, and better compositions because you’re not waiting for fifty tourists to move.

Check Google Maps satellite view for roads that dead-end near cliffs or abandoned churches. Those are your spots.

Nobody ever regretted missing a crowd.