I am playing piano as a hobby, but I am putting a lot of effort into perfecting the pieces I like. Specifically, I am playing Chopin nocturne in c sharp minor and although I am playing it for a while, I have around 50 percent chance to mess up the long fast scale at the end (and when I don't mess up, I play it perfectly). Is there anything special I need to do in my practice beyond just repeating this scales many time to get more consistent?