The Settings button in the top bar takes you to a list of your subscribed threads.

You are automatically subscribed to every thread you post to, though the thread tools button lets you sort it into a folder.

(I don't understand how to sort generic subscribed threads into folders so I have to unsub and resub if I want to file it.)

Mostly I just browse via the New Posts button though, so I see things across all the subforums.