Probably going to met with ridicule because 'ha ha, scrubby silver boi', but hear me out.
I have played a lot of games over the 5+ years I've been here, and I swear what loses most games out everything I've witnessed is people's own pigheadedness. Let's just take my last game for example (not my best showing but bear with me). We had a Lissandra mid that got really cocky because of her high burst and was trying to be the team leader. Only she spent most of the game belittling everyone. And didn't really respect the enemy team (Kai'Sa and Veigar late game being the biggest issues. But she was so sure that her burst would see her through that she began face checking and refused to build anything defensive, so when late game came around, she just exploded to Veigar QR. She just got over confident and got knocked on her ass for it.
Conversely, I had a game a while back where our LeBlanc mid got pretty dumpstered early by the enemy Lissandra. To the point where she said she was going to go afk. But you know what? The team just said 'don't worry, just farm up and scale'. She seemed to calm down from there, she starts getting back into the game and boom, picks up a few kills and dominates for the rest of it.
My point is, letting your ego run rough-shot over you while you're playing. Because it while it does matter what your skill is, game's feel so much easier to win when you don't let your e-peen dictate your attitude.