I was just fine-tuning my follow list on Twitter today and yesterday, and thinking about who I need to follow, and who I don't.
I read a certain blog every day, and that blogger's only posts to Twitter are "something new on my blog today," I don't need to follow that person on Twitter.
If it's a person I might actually like, or want to support, yet their Twitter posts are endlessly boring, mundane or pointless, I don't follow them even though I actually might be interested in 1/10 of what they might post. I don't need to wade through that much clutter, and maybe if enough people un-follow them, they'll figure out that people weren't actually interested in whether or not their Raisin Bran was "so yum!!" this morning.
I follow all kinds of people, mostly not related to the kind of stuff we discuss on this Forum (though I'd be interested to hear of worthwhile ambient music related folks on Twitter). I follow a lot of writers and artists, too, and a few filmmakers and comedians.
Also there are a few news outlets I don't check very often, but they conveniently post notification of all updates to their Twitter feed, so it's a good way to find out when there's something interesting to look at.