Every low elo player should watch MSI
Two of the biggest problems I find in low elo is that 1) teams cannot exploit an early game advantage and snowball the game and 2) If a team is far behind they don't know ow how to stall to get back into the game.
For the first problem watch CLG vs G2. Watch how they move around the map taking objective after objective after objective. Watch how the players who are fed take their advantage to other lanes and get other members on their team fed. They're not doing anything crazy. They're not chasing low health enemies through the jungle. They're not trying to dive 1v3 or 1v4 just because they are ahead. Just very smart efficient play. It was only when they got a commanding lead did they start going for riskier plays in order to crack into the enemy base. Every low elo players should strive to play like this when ahead.
Conversely, for the second problem look at SKT vs RNG. The losing team was immensely far behind but because of excellent vision control and pink ward placement they were able to deny most plays the other team was trying to make. This allowed them to stall out the game for an hour when the game should have been over before the 30 minute mark. Yes they did wind up losing in the end but their ability to stall dispite being at a huge gold deficit was amazing. All low elo players should learn from this game and strive to play like this when they are far behind.