(NewsNation) —  It’s something being seen at more and more businesses: tablets being used as cash registers, that offer multiple options to tip.

As cashiers can see whether people are tipping 15%, 20%, or even nothing at all, some on social media are talking about the pressure that kind of system brings.

Diane Gottsman, founder of The Protocol School of Texas and author of “Modern Etiquette for a Better Life,” said in these instances, it’s best to be prepared.

“You know what’s going to happen. You know they’re going to turn that iPad around,” she said. “Be prepared to hit custom tip or no tip. Now, I don’t encourage skipping a tip for most things. But when you are just being handed a prepackaged sandwich or a coffee that they’ve poured right there, you can feel comfortable either customizing your tip or hitting no tip at all.”

At sit-down restaurants,where people are not making an hourly wage, customers should always tip, even if they’ve gotten bad service, Gottsman said.

“If it’s terrible service, talk to the general manager and let them know,” she said.

But when it comes to take-out, Gottsman said it’s not necessary to tip, although if for a large order with multiple bags, “you’re going to want to leave a little something.”

The person behind the counter is also a consumer in their own lives as well, Gottsman pointed out, so they can understand the angst.

“I think the bottom line is, the more work they put into it, the more effort they put in, that’s how you determine whether or not they’re going to get a tip,” she said. “I think that we do our very best we want to be generous when appropriate. But don’t feel pressured to tip when it’s not necessary as well.”

Watch the full interview with Diane Gottsman in the video player at the top of the page.