I follow a lot of threads by subscribing to them (or posting to them) and then clicking on the little arrow circled in blue that takes me to the "last post read" by me in that thread. Saves a lot of time.
I also use the "archive" option at the bottom of the screen to find new recent threads (as opposed to old threads that someone has just made a new post to). This saves me a lot of time, as I can simply take a look at new threads to pick out those that interest me.
With these options, I usually am not reading more than a page of posts at a time in any one given thread, and often just one or two posts at a time.