I've been writing on and off for many years, and I write every day in my private journal. My approach to article writing is this: if a particular structure comes to mind when I first start (e.g. if it's a listicle), I start with a structure. But if not, I just start writing. I find it quite easy to put subheadings and structure in later if it looks like it needs it. It goes back to my earlier point about first drafts just coming flying out of me with wild abandon. If I've got thoughts in my head that need to be written, trying to force them into a structure in the first draft can sometimes slow me down. I suppose you can liken it to composing music. Often it can be good to just jam with complete creative freedome, then later see what you can shape it into.