Figure out what your goal with this blog post is. Do you want to educate your audience, drive more traffic, rank higher, or get the readers to download an ebook? Basically, what's the first thing you want people to do when they visit your post?
Ask 'why is this post necessary?' How is it going to help your audience?
If the topic has been done too many times, do you have anything more to add to it? Any wisdom that may not already be out there? Most importantly, what's in it for the audience? Why should they read it? Why should they care?
Use free tools like Google Keyword Planner and Keyword Sheeter to look for keywords if you can't afford the likes of SEMRush and Ahrefs. Consider installing SEO Minion extension to analyze your competitors' SEO to build your own SEO strategy.
Create pointers on everything you read. Add your own learnings, expertise, and theories to your pile of research. Airstory by Copyhackers is an excellent tool to compile your research in one place before you start writing.
Break down the post into sub-topics and mark important sections to make it more consumable.
A title is the most important part of any blog post because they're responsible for creating the initial interest. Use tools like Answer the Public and Portent to generate a unique post title that will suit your brand's personality.