I've helped many authors get past writer's block, and experienced it myself more than once as an author, blogger, and book reviewer. There seem to be two main causes: lack of inspiration and fear. I'll address the first one in this article, and save the other equally important cause for another day.
Being a writer without inspiration is a terrible feeling. Just staring at a blank Word document, watching the cursor blink, typing half a line and then deleting it, is the stuff of most writers' worst nightmares. Here are a few ways you can combat that.
Write by hand
Some people have no problem whipping out 2,000 words on a computer, but something about typing my first draft shuts down my creativity every time. But if you give me an envelope and a pen, I'll find myself scribbling till I run out of space, then turning the envelope inside out to keep writing. Not everybody is as inspired by unorthodox writing surfaces as I appear to be, but you should know yourself. Some people feel more connected to what they're writing when they write longhand. Even though it might seem torturous, try it out. If you're already blocked, what do you have to lose?
Distract your brain
Find a physical activity like walking, biking, or jogging that can distract you but doesn't require your complete focus. This will free your mind to wander, make connections, and be creative. Sometimes even driving with the radio turned off will put me into a thoughtful state and help me come up with great ideas. The caveat here is that if you TRY to think of ideas, even while you're jogging, it probably won't work. Try to just let yourself be and the ideas will come.
Read other things
Some writers don't like to read much while they're working on a writing project. I can't imagine not reading, even for a day or two. If you're worried about being too influenced by what you read, try reading in another genre. If you're a novelist, try reading history or poetry. If you're working on a how-to book, try reading a classic novel, or even a bestselling thriller. Seeing how other people write can give you ideas about your own writing -- or show you what you want to avoid.
Going to a new place can be very inspiring, even if it's not very far away. A lot of people get into a rut in their day-to-day lives, shopping at the same stores, seeing the same people, working in the same office. If you can take a weekend or even a day to get away and see something new, it might give you a jump-start in the project you're working on. And if not, you probably spent some quality time seeing something new, which is worthwhile by itself.
Make sure to write down your ideas
I always come up with my best ideas right as I'm drifting off to sleep, in that state between sleep and wakefulness where my mind floats around making connections that I might not make in my totally awake state. I also come up with great ideas in the shower. Basically, any time it's inconvenient to capture an idea, that's when I come up with the best ones. So try to keep a notepad (or an envelope) by your bed, in your purse, in the glove compartment of your car -- anywhere that you might find yourself with a new idea. Then make a big effort to actually write those ideas on paper.
If you try out these ideas, your writer's block won't stand a chance.