I used to have the problem like you. But after I’m using English for a long time, people said that American use “for” but English use “to”. And because I study in American School, so I change my way to use “for” all the time.
There is other explanation:
“For” is often used to express a recipient
E.g.: I suppose, her attitude is an about-face for us.
This sentence means: “you point out that her attitude is (only) for you and your friends”
“To” is often used to express direct towards.
E.g.: I suppose, her attitude is an about-face to us.
This sentence means: “To you, her attitude is very good. You only express your thinking but not really concern about her attitude.”
Besides, there are many words can take either to or for; e.g.: necessary, confined etc.