Hey IH! Recently we decided to start a newsletter but the biggest problem we are currently facing is how to promote the newsletter aggressively. You can visit the landing page here:- https://nlogn.ck.page/1328a48481
Currently, I am trying to build an audience on Twitter and thought that starting a newsletter would also be a fruitful move.
For a start, get on peoples radar. For example, I've noticed I get subscribers for my product (ZeroToUsers) without posting a link. I just comment something useful and some of them go & visit my profile and check me out. You could do the same with Twitter; see which people have engaging posts; comment something useful on them.