I don't often have trouble with writers block. As a big talker it's rare for me to have nothing to say. During deadlines, though, I might freeze; sometimes because I'm working with a new editor and wonder whether I'm on target or not. Sometimes I even get stalled on projects without deadlines, such as my short stories and novel projects. When this happens, I use a variety of techniques to get the words flowing and rev the writing engine.
1) Listen to music. I've often used different types of music to get into the "mood" of a project. While writing The New Deal and the Great Depression (Enslow Publishers, 2000), I listened to Swing. When I wrote several Native American biographies for several specialty encyclopedias for The Gale Group, I listened to Native American flute music. I have a variety of favorite artists across a range of musical tastes and select whichever I feel will help me concentrate.
2) Journal of use a blank computer document. I'll focus on writing anything that comes to might just to get the thoughts rolling. Even if it's, "I have an article due on Friday and I need to focus on getting it done. I want to write about . . ." I keep typing until the words naturally flow into the begin writing the article, which is usually what happens. I then cut and paste the article or story verbiage into a new document (or my original project file) and continue writing.
3) Focus on one part of the project. Try thinking about a character. What is his or her problem? I'll make a list of events that will happen in the story (or points I want to convey in an article). Once I write something on the screen, I usually feel scenes and words coming to mind. Then I switch to a new document and write the story, or turn my list into paragraphs.
5) Switch "location." A change of scenery recharges. If I'm working in my office I might head to the lanai or living room. If that doesn't help, I might grab my laptop and head to a coffee shop or cafe. Sometimes I've even taken my digital recorder and "dictated" during a long walk. (Dragon Speak quickly transcribes which saves time.)
I've been under deadlines on nonfiction projects when nothing was coming to mind and these methods worked. My mind recharged and before I knew it hours had passed and I'd written twice the amount needed. Try a few of these techniques yourself and create your own to recharge stalled writing.