What is different about the stories you write? What is different about the worlds in which you set them? What characteristics would intrigue a reader most and why? There needs to be enough about a character and the world in which they live with which most of us can identify. For example, relationship problems happen everywhere so if said issue happens between two alien beings we can identify with the feelings generated at least. But there should be enough which is different to entice us in as readers so we want to find out more about the world you've created.
I've used geographic features on Earth to help me describe parts of my fictional Fairy Kingdom when I've wanted to flesh that out a bit. (Naturally I can't use anywhere else, given I've got no immediate plans for space travel!). I've also used a little bit of history to help flesh out the way my fictional realm is governed. I've created a world then which is different - how many magical fairy kingdoms do you usually come across in reality?! - but which has features that can be identified with by most readers.
So be different but give us readers the hooks to draw us into that different world.