So, what are some skills / traits of the various ranks?

So, I've been stuck in silver for a while now. Though I've started just destroying lane and carrying (though I don't always win, since I'm usually the only person on my team doing well), so I was just wondering... what exactly do higher-tier players have that I don't? What makes them climb while I sit in silver? Is it really just luck with the matching system, or am I just much worse than I think I am?

What sets apart a silver and a gold player? Silver and plat? etc.

Mechanically, I think I'm fine. I learn champions very quickly and put them to good use. Though, my decision making could use a bit of work, I'll admit. My macro play is fine. I just don't know why I can't climb.