Depending on your field of research, I would suggest that the first step is coming up with a publication tree for the article. In other words, for any given paper idea, figure out the different potential venues the product paper might have. That way you can know what will happen if your first candidate venue rejects the paper. For your own career, there's nothing worse than having papers that cannot be published anywhere which took months or years of your time to write.
Then write the paper with the top candidate venue in mind. Get feedback along the way, etc.
It's not super important to follow their formatting guidelines while initially drafting, because it's purpose-less to master these for any given journal unless that's the only journal you're going to be publishing in. Instead, once the paper is written, then read their formatting guidelines and implement them.
Finally, submit, revise, etc.