If you want get better at pattern avoidences/attacks you might want to record yourself playing then look back at the video to see where to stand etc (I'm assuming that you're playing it blind).
If you want to get better at RNG avoidences/attacks you can practise on more difficult games, something that you'll not expect to beat. I practised on bye the bye. Try games with attacks that you have trouble with, for example: Curving bullets, fast projectiles etc.