To improve acc, play maps that you find very very easy. That way you're not focusing on actually trying to hit the notes, you're focusing on the timing and making sure you are consistently accurate when you hit the note.
Edit od at maps where you already permormance well. Retry maps out of your skill focusing on acc. Play random maps under your skill level to find where you fuck up and improve there.
Worst osu player effort/reward.
Sightreading Pass: 9/08/2018 The Big Black 10/08/2018 Lia - The Never Ending Love (DJ Shimamura's XTC Remix) 10/08/2018 Team.NEKOKAN - Airman ga Taosenai - Blown by the wind 13/08/2018 Camellia - Insecticide - [Arles AR10] 13/08/2018 GYZE - HONESTY 20/08/2018 Seiryu - AO-Infinity
Increase your maximum skill threshold and your accuracy on sub-maximal effort maps will improve. Otherwise work on maps that push you slightly out of your comfort zone and try to become comfortable playing them. In other words git gud and git consistent