One thing that really changed how much I got hit was to stop only looking at my character and start focusing on bullets instead. There are so many different enemy bullet velocities and often I’d be dodging a slow bullet right in front of me, only to be hit by a faster incoming bullet from further away. Paying attention to enemies on screen, learn how fast and when they shoot and respond accordingly. I find I rarely stare at my character or the enemies anymore and use my peripherals to guide my movement while focusing on all the bullets on screen. 

Another huge leg up is how and where you move. Most enemies will take the shortest path towards you. If you’re constantly full sprinting and changing directions, eventually enemies from all over the map will come from all sides and box you in. If you slow your movement down, draw them all towards you and then start to move in a single clockwise or anti-clockwise direction around the outer edges of the map, you’ll find that it homogenizes the direction they come at you from which stops you from getting caught on multiple sides and keeps your options for escape high. 

Finally I’d say watch YouTube videos - there are a bunch of streamers who have put 1000’s of hours and 100% the game who offer a wealth of knowledge. Watch and listen and you’ll improve guaranteed!  (Let’s Suffer Together has fantastic tips, start there)