Prime the pump of your imagination by reading other imaginative works. Here is a review of a couple books for young readers that might open the well of your mind.
Guys Lit Wire: Odd and the Frost Giants by Neil Gaiman and Ludo and the Star Horse by Mary Stewart
http://guyslitwire.blogspot.com/2014/03/odd-and-frost-giants-by-neil-gaiman-and.html?m=1
sharon p. lynn 