7 ways to get over writer's block

1. Step away from the keyboard (or pen and paper). Do something completely different for twenty minutes then return to your writing. This usually helps me reboot my imagination.
2. Re-read what you've written. Of course this only works if you have actually written something already.
3. Look over your notes or synopsis. Try to work out what it is that you're attempting to achieve with this piece of writing. Is your synopsis at fault? Would it be better to change the order of events? Is there a knowledge gap that is preventing you from taking the next step? Are you trying to make your character do something that they just wouldn't do?
4. Write something different. You're stuck on chapter three so write chapter four. Act three is being a pain, so move to act four. Alternatively, if you're a blogger, go write a blog article (perhaps about writer's block). If it's your blog article that's causing your writing muscle to cramp, then revisit that novel or poem that you've been working on.
5. Do twenty minutes research related to your writing. I say twenty minutes because it is not my intention to provide you with an excuse for spending half the day surfing the internet. We all know how reading one blog article can lead to a related newspaper article which in turn... You get the gist. It doesn't have to be anything as material as researching how to cremate a body when your story is set at a cremation. It can be as simple as looking at images of the sea if you're writing about a day at the coast or reading a book in a similar genre to your own story.
6. Ring someone. No, I don't mean send them a text. Pick up the telephone and ring a real, living individual. If nobody is available, then go out and find a real person to talk to. I'm not suggesting that you accost a stranger in the street. It might be that you have a family member at home. Perhaps your neighbour is in their front garden. Failing all that, go down to your local newsagent and chat to the cashier as you pay for your newspaper (probably best to buy something rather than just go in and strike up a conversation). The point here is that listening to a real human interchange relinks you with the rhythm of living, breathing speech which after all is what we are trying to portray in our writing.
7. Just write. If everything else fails and your muse still refuses to get out of bed, then simply put pen to paper or fingers to keyboard and write. It doesn't matter if it makes sense. I don't care if it's complete twaddle. For twenty minutes, write what comes into your head and your heart. You never know. You may surprise yourself and find a masterpiece in the chaos.