There is no single best way to begin a writing project. What's best is what gets you going and builds momentum for the journey ahead. You may want to start right in on a draft or do some pre-planning.
Often, simply Choosing a Subject can be a challenge. You could start Freewriting to locate your subject and generate ideas. Or you might prefer to first gather information from Outside Sources, or to brainstorm using The Journalists' Questions.
Whether you're writing an informal essay, a technical report, or the next great American novel, the suggestions in Discovering What to Write will help you get going.