The quickest way to get thrown on a big pile of irrelevancy is to be a "me too" social drone. This is when a lot of what you share contains too much of the trendy stuff that a lot of others have already shared.
Many people apparently think that being a good curator means sharing things that have already become popular. As Dr. Phil would say, "How's that workin' for ya?"
So what is the secret sauce that makes people like Guy Kawasaki, Robert Scoble, or Mari Smith popular while most everyone else remains hidden?
In a word: Sources.
If you pick through the same RSS feeds and all the usual suspects in your niche, you're going to end up sharing the same stuff everyone else in your niche shares. Everyone looks the same and it's impossible for a prospective follower to choose any one person to follow that way.
The reason some people gain huge following on social media through curating great stuff is that they share things that don't get picked up by everyone else. Things that are interesting, important, entertaining or otherwise valuable to their audiences but that somehow were missed by the others in your market.
In order to get this sort of secret edge in social curation, you have to find things you weren't even looking for. And this means you have to use tools beyond just following RSS feeds in Google Reader. Sometimes you just don't know what you're looking for and it's not going to be in the feeds you subscribe to all the time.
So you have to be open to memes and watch what's trending on Google+, Twitter, and other trending topic tools. I won't name everything here, because curators are better when they find sources themselves and kind of keep them a secret.
Suffice it to say that there are tons of interesting tools popping up all the time that give you an entirely different view of a trend with sources of content you've never heard of before. That's when you know you've struck gold. You're looking for sites and stories that the mainstream misses because they only use the most obvious sources.
For example, I almost never post anything from Mashable.com on any of my social accounts. Why? Because it's guaranteed that someone already has and that hundreds, even thousands of people will soon. It gives me no edge whatsoever to post things from such a big target that amateurs curate from all day long.
An Easy Curation Trick
One way to find really coll cool sources is to go to the obvious places in your niche and then follow links to find their sources. The reason everyone loves the big sites' stuff is because they find unusual stories that haven't already been beaten to death. So where are they getting them?
Follow the links and you'll soon find out. You aren't breaking news by sharing something from a huge site in your niche. THEY broke the news. You're just passing it around. Sometimes that goes a long way if you're first to share it. But most of the time you're just performing your drone duties and merely supplying the Queen with resources and nothing for yourself.
To bend the web like the pros do, you have to go to the sources of the sources everyone else uses for social curation. Go a level or two deeper and be the one that everyone has to "Like" retweet or +1 instead of being a social drone.