What is the best way to use a Charm subtype spell (Friends, Charm Person, Dominate Person/Monster) without being caught?
As you will note in the spell description.
"When the spell ends, the creature knows it was charmed by you."
As you can imagine, most people do not like to be mind controlled, even if it is just to pass a Charisma check. So what is the best way to resolve this issue in-game?