Teach them the rules right from the start!
What you want from your dog when he or she's grown up is what they need to learn when they're pups - how else will they know? This is 16 week old Daisy and 14 week old Sophie learning that even when the door is wide open, coming inside isn't what their people want (no matter how cute young Sophie tries to look!).
Be fair on your teach them the rules right from the start!