Writing is a process of figuring out what you think, not a matter of recording already developed thoughts. Since it’s not possible to think about everything all at once, most experienced writers handle a piece of writing in stages. You will generally move from planning to drafting to revising, but as your ideas develop, you will find yourself circling back and returning to earlier stages.
Before composing a first draft, spend some time generating ideas. Mull over your subject while listening to music, taking a walk, or driving to work; or jot down inspirations or explore your questions with a willing listener. Consider these questions: What do you find puzzling, striking, or interesting about your subject? What would you like to know more about? Be curious and open to new ideas and different points of view. Explore questions you don’t have answers to.