first, i am not a "writer." i generally don't respect people who call themselves writers. imagine calling yourself a Speaker. i suppose you're claiming ideas worth sharing. in that case, just share your ideas!
because i am not a writer, i do not think too much about word choice or grammar or the flow of my prose. i don't draft outlines or research anything at all. if an argument is not ready to rock at my fingertips i do not scour the web for confirming evidence. this is the path of A+ teacher's pets. i dated one of those in high school. she went to an Ivy League and now works in customer service.
but i can tell you where article ideas come from: arguments in my head. we are input machines, always absorbing little tidbits about the world. sometimes these tidbits have enough teeth to stick around in our noggin. and when enough tidbits bounce around the same space, they fight. whenever a tidbit (notion, argument, idea) wins one of these internal battles i tend to upgrade it to a bullet point in my todo list:
POST - how X is like Y"
POST - on Xing in order to Ying
a few days or weeks later while procrastinating from making money i look at this short list of blog post ideas, grab one and go. from my inventory of 100s of posts since 2012, at least 90% were written in < 1 hour. putting them to paper is the final boss battle determining which idea really "won" in my brain's background job. and i can admit sometimes at the halfway point of a post i realize the idea didn't really win, so it's back to the gulag. aka the todo list bullet point is swiftly cmd+backspaced.
so to answer your question, unlike in software development i do not have a process for blog posts. it's a spontaneous, low energy and low effort investment that has ironically paid better dividends than many other projects where more planning was involved. this isn't a swipe against planning, just a swipe against "writing."