Mentioned in another post for a story idea, I think it would be interesting to create an atypical fantasy world. Sure, it has your elves, dwarves, spells, swords, etc. But the races are not all in harmony fighting one big bad guy. Rather, the races are all at war. The out and out hostility elves and dwarves infamously have for each other is full on bloodshed. Each race fights the others, nervously eyeing those of another race.
Could make for some interesting stories highlighting the problems with stereotypes, racism, and over-paranoia in our modern society. Plus, it’d just be a cool, weird place to have adventures and write stories. The obvious character group would be a set of mixed race adventurers forced to work together and trust each other.