RSS and apathy for things like webcomics and blogs. For things like forums, I can generally only maintain interest in one forum over a span of time. One of the nice things about Discourse is that it has enough AJAX built into it that I don’t have to refresh constantly. Just keep the Topics page open and wait until it tells me I have unread stuff. If I had two forums that behaved that way, I could keep up with … three. And so on.
I found out during my Twitter-obsession days that “keeping up with” media is way too easy for me to get stressed about so I largely don’t bother. If I’m interested, I’ll poke at it when I’ve a mind. Otherwise, blissful–and peaceful–ignorance.