Advice: Play for hours, but take lots and lots of breaks! it will refresh you every time especially if you aren't playing your best.
2nd Advice: Always use 0 AR, and lower your DAS as much as you can play comfortably. Its worth getting used to lower DAS. Personally I think 3-6 DAS is humanly possible because I can play on them, but go with whatever makes your hands feel nicey nice.
3rd Advice: Set a short term goal and watch somebody who has a replay that fast, so you will know how fast you should go
4th Advice: Always get good circulation in your forearms to your hands, it lets you play faster and you can avoid carpal tunnel.
This helped contribute to me getting sub 30 in about a week from me coming back from a 1 year break!