Number 1: Pick a subject that almost no one in the world even knows exists.
Number 2: Choose an angle that no normal person would choose, and which will infuriate all the "normies"- if they ever discover your blog. Which, if you do item 1 right, they won't.
Number 3: Even though you don't get much attention, don't change anything substantive trying to get noticed.
Number 4: Keep it up. Don't quit.
Added recently- Number 5: Make videos which can be ignored by billions of people worldwide.
OK. Slightly more seriously...
I find I have the best blog ideas (well, the ones I think are best, anyway) while I am doing completely unrelated things. Things like taking a shower, mowing, making something, or sitting and waiting. Things that don't require much thought, but also don't put me to sleep. (But falling asleep at night is when I also have ideas.) That's when my bored mind starts working and pasting together thoughts inspired by things I have read or heard or which just form in my mind from who-knows-where. Before I know it, a full-blown blog post will be rattling around in my skull, just waiting for me to either write it down, or forget what it was.
If I am smart, I quickly stop and text the idea to my email (or, make a conscious mental note, at least), otherwise I usually forget what I was thinking and miss the chance. I really hate when I forget one, but I still haven't learned to "save" them every time- I always think "I'll remember this for sure!".
If you do it right, after a decade or so you'll have literally dozens of people reading your blog every day. Only the best people, of course, not those other ones.
-If you get any value from my labors, consider rewarding me with your financial support. This blog is in its 10th year now. If you believe I have contributed anything to the conversation regarding liberty during these ten years, and believe I have more to contribute, help me stay online.