The answer is simple: YOU are what makes your story worth telling. Harry Potter wasn't an original story, and yet told very well, it became an excellent series.



My suggestion to you is to ask what unique passions or life experiences you have that aren't found in the average fantasy book. This genre still has a lot of room to grow. A person passionate about sports could write a very different fantasy novel from one passionate about lawn care--assuming they take what they know and love and make us, as readers, come to know and love it as well.



Good luck!