The main problem is that a lot of sites no longer show a link to their RSS feeds, or include a meta tag for it.

So I've resorted to trying the following until the RSS reed comes up:

  example.com/feed
  example.com/feed.xml
  example.com/rss
  example.com/rss.xml
  example.com/xml
  ...etc

In most cases the feed WILL be there somewhere as the feature is still in the web framework that's being used.