if i were u i would ........

"I advise you to" "My advice to you would be..." "If I were you, I would..." "Why don't you..."

'I think that... maybe you shouldn't tell her that.' 'Perhaps you should... talk to him about it later'

"to" is used (perhaps illogically) because we "give advice to someone". Nevertheless we do use it in the way you show. This is my advice for you. is grammatically correct but not so idiomatic

I advice you to