I've been working (and by working, I mean idle daydreaming) of a micro setting based around a tropical island where the classic species and monsters aren't present. The island natives are tabaxi, aarakroca, sea elves, tritons, lizardfolk, tortles, and flamekin (like fire genasi) and monsters would be dinosaurs, sahuagin, yuan-ti, and other tropical monsters of the land and sea. The PCs are either natives or shipwrecked on the island. The biggest goal was to experiment with things you don't normally see and skip the Tolkien stuff in favor of exotic stuff.