I usually tweet WIP screenshots and tease whats coming, then I do a public launch on PH, LinkedIn, Facebook groups and Indie Hackers. But always before bulding a microstartup, I have the organic growth channel figured out. For example with https://visalist.io it was SEO, with https://anexplorer.co it's ASO

I put all my focus on one when i'm getting started, but after its feature complete then i move on to the next. I spend around 20% of my time improving/fixing existing ones.