1. Pick the region from your season, not your Pinterest board
Every region has months where hopping simply does not work. The Andaman coast shuts down in the southwest monsoon; the Philippines gets typhoons from September; the Caribbean has a hurricane peak in September and October; the Cyclades close most hotels from November to March.
Start with when you can travel, then choose from the regions that are in season. It is the single decision that prevents the most disappointment.