A lot of us can get caught up in the sheer pleasure of shopping. Sometimes we get something we aren't super into but we still wear it because it feels like a waste if we don't.
You don't have to fall into this trap! Only buy something if you love it, and if it's not what you thought it would be, then return or exchange it for something else.
When you wear something you like, you will own that look and have fun doing it. That's confidence right there. Owning what you've got, having fun and loving it regardless of any others' opposing opinions.