> is there a reliable way to find an RSS feed for a given site, assuming it has one?

Any half-decent feed reader app will do it for you after just pasting the website’s address.

> Are there good tools to RSSify sites that don’t have one?

https://openrss.org

https://rss-bridge.org

https://createfeed.fivefilters.org

And for newsletters:

https://notifier.in

https://kill-the-newsletter.com

Awesome, thanks! Especially for the pointers to those rssifiers.

For the first question, I should clarify that I'm hoping to just ingest these RSS feeds myself in various scripts. But yeah, makes sense that most of the good feed readers mostly take care of that.