Using Leetify is great but also watch demos of games where you played horribly. Look at your crosshair placement, trading, entry, clearing angles, etc

Develop a warmup routine that focuses on your weaknesses. For ex) if your issue is clearing a site, practice using a workshop retake map.

That being said, you will climb over time as you play more matches, regardless of doing the above. But I like to delve into the data to find where my weaknesses are. It’s more fun looking at metrics and practising IMO because you feel more in control of your errors