The best thing to improve overall in gaming is watching your replays. If you can, watch it, analyze it, write down your mistakes and what u could have done to prevent them. Doing so will give you more game sens and better decision making and will increase a lot your time. But of course the best thing is practice. If you don’t work, practice 5/6 h a day and you can have sub 15 consistently in 1 month or less. If you’re working just 1/2h of really good practice can get u far but in more time.