Don’t get caught short-changing for a job well done. We asked our trusted advisors Peter Bonventre and John Jannuzzi to give us their tips on tipping.

Peter Bonventre

Americans are the best tippers in the world, and the best of the best are New Yorkers. As someone who’s travelled far and wide, that’s my considered opinion, and I’m sticking to it. Sometimes I think it’s baked into our DNA. Okay, I will concede that for some status-conscious New Yorkers tipping large is the fashionable thing to do.

For most of us, tipping is simply an expression of gratitude for a job well done. That’s why a tip is also called a gratuity. Let some of these customary tips be your guide: Give a barber, taxi driver, or the pizza delivery guy 15 percent of the bill. A bellhop deserves at least two or three dollars a bag for lugging your luggage up to the room, and the maid should get four or five dollars a night for cleaning it. The valet or the garage guy who brings you your car? Two bucks. And if you’re smart, you’ll tip the doormen and the super of your apartment building each time they render a service that makes your life a little easier—a few simoleons will get you a lot of good will.

While I generally base my tip on a job’s quality, I don’t think I’ve ever stiffed a waiter or a bartender. Even a crappy one will get 10 percent from me. He or she should’ve received the customary 15 to 20 percent if they’d only had sense enough to treat me well. I’m always mindful that these folks are generally paid less than the minimum wage, and their livelihoods depend on tips.

Here’s where I tell you the best tipster story ever. One night outside a restaurant, Frank Sinatra asked the valet who brought him his car what was the biggest tip he ever got. The valet said it was 100 bucks. Sinatra slipped him 200, and before driving away, asked who gave him the 100.  The valet replied, “You did, Mr. Sinatra.”

John Jannuzzi

I wish we could just start the tipping world over. Honestly. But we can’t. We’ve conditioned ourselves to throw an extra 20% on to every restaurant bill, throw the cabbie a few extra dollars, or slip the bellman a few bucks for the bags. It’s exhausting, really. It’s nobody’s fault, though.

Since we’ve become so accustomed to tipping, people have become accustomed to relying on it. A waiter often makes their living off of gratuities, and we cannot deny them that. When I worked as a coat check for a few years, I relied on tips for a cab home at 2:00 in the morning, or maybe a stop at the bodega on the way home. I loved the tips, I earned them, I needed them. As a customer, the idea of paying an extra fifth of my bill seems outrageous, but I always do it, because I know somebody is depending on it–and I’ve been there. Even the poorest of service gets 18% from my wallet.

My general rule of thumb is: always tip. You tip your waiter, your coat check, your doorman and dry cleaner over the holidays, you add a few bucks to the cab tab, and drop the spare change for the barista. It doesn’t feel great to part with the extra dollars here and there, but it’s the right thing to do. That said, I love visiting a foreign country, where tipping isn’t customary. Suddenly, everything is cheaper.

But, everybody has different rules, and to understand them, I always look to Google. God of knowledge.