screw (something) up
Definition: to crumple something, such as paper or material, using your hands.
(This phrasal verb has more than one meaning)
E.g.1: When he realised he had made another mistake, he screwed up the piece of paper and threw it into the bin.
E.g.2: I’m sorry my homework is creased, but my baby sister found it and screwed it up.
This phrasal verb can be separated. (E.g.2)