Why you are bad (low elo)
Now im not someone who is amazing at league but i am above average and here's some reasons why you are just average (silver) or bad (bronze)
Blame, you never admit when you messed up you always make a reason to why you died or lost lane, i.e blaming jg for not ganking or blaming a teammate for not following up even though the engage into a 2v4 was dumb
listening skills, recently i was on my smurf in silver elo and queued with an adc main; we were at 40 mins in, had both mid and bot inhib turret down so we grouped top to get last turret get inhib and rotate down, i told my partner to stay top, he went mid to try and get inhib solo because he thought top was a bad call, he died we got aced and they won, all he had to do was listen and we would've won but like most low elo players he believed what he thought was right when in actuality it was very wrong. it doesn't hurt to listen to teammates when its a safe call
Critical thinking, like stated above most of the time you make bad calls or do the wrong thing simply because you thought it was right but thats why you are low elo Scenario: you are a fed adc your team wants you to group at baron because enemy jungler showed bot lane, instead you go try to 1v1 him whilst your team is at baron enemy team sees you bot lane so they contest baron and win, you got the 1v1 but you're the only one alive now plus the enemy has baron, ive seen this happen so many times, making the wrong decision at a critical time is a big part to why you're low elo
Insanity, making the same mistake over and over again but expecting a different result. Say you are playing thresh and every time you go to hook the enemy back steps, well a good player would adapt, start throwing the hook behind the player and watch him back step into it, low elo tends to just do the same thing every time, throw the hook straight at him expecting a different result. this was a pretty specific situation but can be applied to most of the game with a lot of champions
So the conclusion is take something from this and apply it, start admitting to your mistakes, listen to teammates for god sakes you aren't a god at the game so what they are saying might be correct, make safer better decisions that benefit the team, adapt to situations differently and don't continue to do that same thing if that thing isn't working. There is more to league than just this, but these things helped me climb and continue to climb[: