You know to tip the waitress and the bartender. But should you tip the barista at Starbucks? What about the guy who washes your car?

It can get confusing on who and when to tip.

Diane Gottsman is an etiquette expert and author of the book, “Modern Etiquette for a Better Life.”

“You look at the industry, and you tip service providers that work for gratuity,” Gottsman said.

People who wait tables, valet your car and serve you drinks, that makes sense. But what about the Starbucks barista? Gottsman says you can tip a dollar or two, but it’s not a must.

“I know there’s the tip line. It’s not mandatory. It’s like the tip jar. It’s not obligatory. It does not mean I have to put change in that,” Gottsman said.

Another one that can be confusing is Uber drivers. The company says you don’t have to, but should you?

“It’s the right thing to do. It’s the nice thing to do,” Gottsman said.

Who else should you tip? This is what Gottsman advises in her book “Modern Etiquette for a Better Life”:

  • Food server - 18-20%
  • Food delivery - 18-20%
  • Bartender - $1 per drink
  • Manicure/pedicure/massage - 15-20%
  • Flower delivery - $5
  • Shuttle driver - $1-$2 per bag
  • Restaurant valet - $5 upon retrieval of vehicle
  • Hair stylist - 15% of service
  • Shampoo attendant - $3-$5

Tiffany Craig sat down and talked with Gottsman about tipping, social media and work etiquette. Watch the interview here.