Sarah Ferguson warned her daughters "no one wants to see a grumpy princess".
The Duchess of York explained politeness has always been "entrenched" in her and she hoped she'd passed the quality down to Princesses Beatrice and Eugenie - who she has with ex-husband Prince Andrew - and she revealed one of the most important pieces of advice she had given them was not to make public appearances if they couldn't "get [their] game on".
Speaking on her 'Tea Talks' podcast, she said: “I always say to my girls, when you’re out on the public stage, smile. If you don’t want to be polite, don’t go out on the public stage — because no one wants to see a grumpy princess.
“I think the most important thing is you've got to get your game on.”
The 63-year-old author also shared some etiquette tips, including how to move on to speak to another guest at a party without making the first person feelsnubbed.
She laughed and said: "Well, it depends which country you're in. There's all different cultures which you must always be aware of, and I love that.
“If you're in British Downton Abbey, you get to a point when you say, ‘One second, could you hold that thought because I’ve just got to go and see Fred over there because I’ve got to give him a message.'
"And by the time that the person you’re talking to has gone onto the next subject, they’ve forgotten that you were coming back to tell something about Fred.”
Sarah also revealed how to dodge talking about an uncomfortable subject.
She said: “If someone asks you a tricky question that you don’t want to answer, say ‘Oh that’s so interesting, I’ll tell you what, I’m going to throw that question to Matilda. Matilda, what do you think about that question?’ And you’ve thrown the ball again."
And when it comes to juggling a busy social calendar, the duchess has learned to make a brief appearance at each event "very loudly".
Explaining how she juggles multiple engagements in one evening, she said: “What you do is you walk through the door, go in very loudly and walk all the way around the room. And you’ll be so loud that most people are going, ‘Oh my goodness, it’s so loud.' Then you leave after five minutes, and so the host and everyone will say, 'Oh, I didn’t see Sarah tonight.’ And everyone in the room says, 'Oh, well we did.' "
Tagged in Sarah Ferguson Princess Beatrice