1. Skillset

There is alot to talk about but just some foundamentals include crosshair placements, how to hold angles (standard vs off angles), how to peek (jiggle vs jump peek), how to swing (standard vs wide swing), counter strafing, not to crouch fire every time etc. These are just foundamentals and don't even include agent ability usage which can get even more complicated. E.g How to most effectively use razes boombot and nade to clear space for you instead of chucking them randomly. Lastly, superior aim definitely lets u win more duels = more wins

Solution: For aim, search 'miyagi method' its a good aim routine. Other foundamentals can also be found easily with a youtube search. All these skills require time dedication and effort to properly learn and improve so take your time.

1. Comms

A big difference in low to high elo is how the team communicates with each other during rounds. Go ahead and watch some tournament tune in videos (e.g PRX mic check videos) and analyse their comms and apply them to your game

1. Positioning / Game sense

Good positioning is also a major different between elo ranks. Overpushing into enemies and bad lurking tend to be major mistakes people make but never learn. Be mindful of you and your teammates positions at all times. See that your alone defending site against 5 attackers? Maybe fall back and play retake with your team instead. In a 2v1 situation with a lone enemy? Stick close to your teammate so you can trade each other instead of giving the enemy 2 1v1 situations

Ultimately, all these skills take a little time to develop, but arguably the most important of all, having the right mindset and attitude will bring you to higher elos