I would like to know how to stop following a thread that I have had interest in but not anymore, feel is going on too long, being trolled etc. Can't figure how to turn those off. Maybe there is not yet a mechanism to stop following something. I for one like that option.
menu Forums | Watched threads
...Then, checkbox the threads you want to stop watching and, at the bottom right of the page, click the [With selected...] dropdown menu, select [Stop watching] and click the [Go] button.
The default user setting is to automatically watch threads that you reply to, but you can switch it off.