Discipline Methods

How do you guys discipline your LO? My daughter doesn’t listen not one bit, even after making it clear that I’m serious. She thinks it’s her way or no way literally 😭. Sometimes it’s easier for me to just let her do what she wants, but that does not work out all the way. Currently she’s having a tantrum because I won’t let her have anymore candy and she keeps going back doing it after I said no. 😩. I’ve tried time out which absolutely doesn’t work