You can find RSS feeds by adding `/feed` to the end of a WordPress website's URL, `rss` to the end of a Tumblr site's URL, or `feeds/posts/default` to the end of a Blogger site's URL. For other sites, you can try searching for "rss" in the source code or use online tools like Zapier to create custom RSS feeds from data from thousands of apps and services. You can also find YouTube channel pages as RSS feeds by copying and pasting their URLs into your reader. Additionally, many RSS readers can automatically pull a source's feed for you if you can't find an RSS feed URL using the methods mentioned above.