I'm just going to copy my advice from another thread on the same subject.
You have to adapt to the ELO you are in.; the champions, playstyles and strategies which work well in Gold will not necessarily work in Silver.
From what I recall of my time in Silver last season, I identified four main weaknesses that I sought to exploit:
[1] Players typically have poor general skills in lane.
Players don't really know how to manage minion waves, trade proficiently, shut down opponents or roam. Due to this, it's really quite easy to get ahead as a mid- to late-game scaling champion (i.e. Wukong, Nasus, Irelia) without falling behind and even snowballing early.
Also, players often overextend or ward poorly so you can often get fed rather quickly when jungling if you have strong early ganks (i.e. Volibear, Xin Zhao, Kindred).
[2] Players tend to group around objectives constantly and/or at bad times (they don't rotate well).
Honestly, a lot of my matches devolved into essentially ARAM. Both teams would group around an objective (i.e. a tower, inhibitor, dragon, baron) and proceed to spend the next couple minutes walking around it and exchanging poke until somebody gets caught out or sloppily engages a teamfight. I got a lot of use out of Ziggs (mid) and Varus (ADC) during these times since I could easily disengage fights, poke them down, or pick someone off.
[3] Teams tend to lack durability and CC
This isn't always true but I ran into many teams composed highly of squishy, high-damage and low CC champions in Silver. To compensate for this, my champions would usually at least have one strong CC ability and/or some durability to fill this gap.
It's hilarious how having even one durable fighter/tank and/or some AoE CC can change a fight against a team of carries. The ability to engage/disengage fights or pick people off is massive.
[4] Very, very few people know how to support properly.
Support seems to be the role that people are usually forced into playing (at least before dynamic queue). As such, it was typically filled by a player inexperienced with the role and a good support could be extremely influential (since they didn't have to worry about the other support countering them).
As such, an experienced support player would (even with a poor ADC) be able to dominate bottom lane. After crushing the enemy bottom lane and when their ADC is back, supports can roam mid or support their jungler during an invade to spread their lead and get their other allies ahead while shutting down their enemies.
Obviously, I would recommend playing champions you love and who you are experienced with. However, I would recommend you take a look at what mistakes or trends appear during every game and think on how you can exploit them.
