How to get cat to stop scratching furniture?

My fiancé and I adopted a 4 year old Siamese about a month and a half ago. She is the sweetest, cuddliest thing - except she only scratches couches and our headboard! We bought her a cat tree with 4 scratching posts, several toys, scratchy toys, but she won’t stop scratching what she shouldn’t. We’ve tried taking her paw and putting it against the posts, carrying her to it when she scratches something she shouldn’t, tried playing with her with her scratchy toys - nothing. She has 0 interest in the cat tower, and the posts and toys - she likes small balls with bells in them but that’s about it. I don’t want to spray her with water or get her declawed but she just doesn’t seem to understand no, or what we’re trying to show her. Advice? I love her very much.

EDIT: forgot to mention we tried cat caps and she just chewed them off or had an attack when we put them on.