I do a competitor analysis and analyse the content for the sites who are ranking for those particular keywords. Further, I try to find the content gap and then on the basis of that I write content (not bothered about the length tbh)
It is good if you are using it wisely. I don't consider myself as a champ or expert but I do a lot tweaks and keep on checking on Google Keyword planner + manual G search.
Pillar topic would be the main article and further articles will give links to the pillar content. From pillar the link will go to the authority site (I generally use wikipedia)