League of Legends (LoL) Question: Bans

You can always check this site for statistically optimal bans. It's updated often and sorted by rank.

Yasuo, Darius, Katarina. Low elos are very bad at shutting down and beating these champions effectively

Support: Blitz Sona Miss Fortune Janna
ADC: Jhin Lucian Ezreal Tristana
Mid: Brand Yasuo Katarina Akali
Jung: Warwick Rengar Lee sin
Top: Pantheon Ryze Teemo Jayce

I mostly ban TF champs that will cause trouble. Depending on the style of game, team composition, I mostly ban these :
BlitzCrank, if team don't have much escape.
Veigar, for its passive.
Lux, if team don't have poke.
Braum, if team is focused at skillshots.
Yasuo, if team is focused at skillshots and have low mobility.
Lee Sin, if team has low mobility.
Morgana, if team is focused on CC.
And much others.

Good bans for low elo generally tend to be champions who can snowball heavily off of one or two kills such as: Katarina, Yasuo , annie, Zed, Fiora , darius , jax , fizz , rengar and yi.

From what i've seen from my friend's games, zed, xin, darius and kata are still popular bans in silver.