I was thinking of starting a mailing list but I just can't figure out what will be my niche.
Do you have a mailing list? how did you figured out what is your thing?
Can I just start a list and write about general things that interests me? I suppose it'll be hard to grow that way.
what's your advice?
The book by David Epstein: “Range - Why generalists triumph in a specialized world” might be an interesting read for you.
https://davidepstein.com/the-range/