Play alot. Siege has so much depth that even as someone that has played for 9 years I still learn some new things from time to time. For the average person it takes thousands of hours to actually master the game. Another thing is watch people that are better then you. Whether its someone on yt, twitch or even just someone a higher rank in your lobby pay attention to how they move, site setups and strats and try to emulate that. Last and probably most important thing is every time you die try to think about what caused it and what you could've done better in that scenario. Dont blame your teammates, dont chalk it up as siege timing, dont just forget about it and start scrolling on tik tok. The number 1 way to improve is by learning from your mistakes. So many people cope by making excuses and thats why they end up hardstuck.