When I first started using Twitter, I had some basic rules for reducing the noise and increasing the value... following them made it a better experience for me.
After scanning through this mornings feed on G+, it seems like I need to bring back those rules (as applicable to G+.)
1) If I mute 3 of your posts in a single day, you're gone.
2) If you post about religion or politics more than anything else, you're gone.
3) If you post incessantly about the latest world crisis more than anything else, you're gone. (I have other sources for news.)
4) If the only things you post are marketing fluff, you're gone.
5) Adding me to a circle doesn't mean I'll add you, but I'll check out the incoming feed.
6) The more friends we have in common, the more likely I'll add you.
I've already enforced rules 1 & 3 today and it's barely 10am.