Okay, if you want to catch actively updated works on Archive of Our Own, here's my favorite way to hunt them down and stay notified — it’s a little nerdy but it works. First, use the site’s search and sort features: search your fandom (for instance, 'My Hero Academia' or 'Harry Potter'), then sort by 'Date updated'. Filter by 'Works in progress' or include the tag 'WIP' to see serials that are still being written. The 'last updated' timestamp and recent comments are the quickest clues that an author is posting new chapters.
Beyond the site itself, I rely on RSS feeds. AO3 exposes feeds for searches, tags, and even authors; drop a tag or a query into an RSS reader and you’ll get a steady stream of updates without refreshing the page. If you want push notifications, I use an RSS-to-phone app so new chapters buzz my pocket. Another trick: follow authors on Twitter/X, Tumblr, or their Patreon pages — many announce chapter drops there first. Also, I bookmark works I’m tracking on AO3 and add a quick note in my browser bookmarks folder (like "check weekly") so nothing slips through.
If you prefer social proof, sort by bookmarks or kudos in addition to date updated; works that get a lot of engagement tend to have authors who keep momentum. Look for author notes that say something like "update schedule" or "next chapter soon" — those are gold. Honestly, once you set up a small system (tag search + RSS + author follow), you’ll feel like you have a miniature update radar for all your favorite fandoms.