How to treat a girl nice but not end in the friendzone

[bat soup]

Im asking this question because of not enough experience with girls im 20 years old. Where is the line between treating girls good like a gentleman and being too nice like a simp. My only experience was when I treated girls bad they liked me more sexually than the ones I treated like a friend.
So how do I need to treat them for more than just becoming friends?

You can say nice things whilst sliding your hand between their legs.