Before you even begin to write, develop a working headline or title for your piece. Like a compass, it will give you a touchstone to return to if you start to drift. You may think that something as short as a 1000-word article doesn't need an outline, but the short length actually makes an outline all the more critical. The idea is to spend some time thinking about the piece as a whole before you put pen to paper, or fingers to keyboard. Thinking about the article holistically allows your brain to begin to formulate a logical structure, effective transitions, and an appropriate introduction and conclusion.
Outlines are also the best insurance against writer's block.
With an outline on hand, you'll never have that problem. By allocating approximate word counts before you begin to write, you'll know how much you can say about each topic area of your article. This budgeting will also help you determine how long it will take to write the various sections, as well as where you'll need to do additional research to beef up your points. Once you've created your outline and budgeted words, you're ready to start filling in the gaps and come up with a first draft. There are different ways to get going.