Take a break and experience some new things, like movies, music, games or hobbies. I had a similar thing when it came to signature tags in Photoshop. I had a period where I was stagnant and I do believe that it was mostly due to what I was naturally exposing myself to.

So I'll take an example of music, but most people that know music are generally used to drums and guitars. However there is more out there when you look at DJs and how they rely on computers and turn tables. Some even borrow other music tracks and use them as samples.
Example: [url=http://youtu.be/eU5Dn-WaElI]Making of "The Prodigy - Smack My Bitch Up" in Ableton by Jim Pavloff[/url]

I could go a step further and say that you don't even need samples or musical instruments to make music. How about a gameboy? [url=http://youtu.be/LJck6Md7iIM]Skip Cloud - SLNCE IS GLDEN[/url]

So you see a simple thing like creating music can have so many possibilities where people that don't even own a musical instruments can produce something. The exact same can be applied to story writing. Read a couple of books you normally wouldn't touch, watch a TV or even anime series that you don't know about, or even watch a movie. What you are looking for is something in that form of media to grasp your attention to the point where you want more or even want to share with others what you enjoy.

Hope that helps.