Self-checkout was supposed to make shopping faster and easier for everyone. But as anyone who has waged a war with the bagging area knows, it has also introduced a whole new frontier of frustration.“Ugh. Where to begin?” Jodi R.R. Smith, the president of Mannersmith Etiquette Consulting, told HuffPost. “Self-checkout is great for when you pop in somewhere and need to grab a handful of items or a quick bite to eat. However, they are simply not designed well for a big shopping [trip].”“It is difficult to bag, and if the customer has a full shopping cart, the logistics quickly become problematic,” she elaborated. “And don’t even get me started on the poor soul of an employee who is charged with watching all the customers for shoplifting, while fixing the stations as they perpetually glitch.”And yet, some people manage to make an already imperfect experience even worse.“Unfortunately, it looks like these machines are here to stay, which means polite customers need to know how to best navigate them,” Smith said. To help make the process less frustrating, HuffPost asked Smith and other etiquette experts to share some common rude behaviors they’ve observed at self-checkout ― and what you should do instead.Ignoring Rules About Item Limits“Be mindful of the signs,” said Nick Leighton, an etiquette expert and host of the “Were You Raised by Wolves?” podcast. “Some places limit the self-checkout machines to a certain number of items or fewer. You know how many items you have. Don’t try to be sneaky.”Indeed, stores like Target have a 10-item limit for self-checkout, but on busy shopping days, it seems not every customer abides by this. “Follow item-limit guidelines,” echoed Thomas Farley, aka Mister Manners. “Don’t try to sneak in more than what the limit indicates.”Leaving A Mess Behind“Don’t leave a mess behind,” Leighton urged. “Took out too many bags? One of your deli items leaked all over the scanner? Clean it up yourself or loop in a staff member. Don’t just leave it for the next customer to discover.”Similarly, be mindful of any items you ultimately decide not to purchase. “Don’t abandon your rejects,” Leighton said. “If you changed your mind about that ice cream, don’t just leave it there. It’s your responsibility to ensure it makes it back to the right place.”Grace Cary via Getty ImagesSome people manage to make an already imperfect experience even worse.Encroaching On Other People’s Space“In the tighter self-checkout spaces, do your best to keep your cart as close to you as possible,” Smith said.Even and especially on busy days at a crowded store, it’s important to be respectful of your fellow shoppers. “Give the departing customer in front of you ample room ― and time ― to leave,” Farley advised. “Don’t start scanning your items while they are still packing their bags at the same station.”Getting Hostile With StaffWe’ve probably all dealt with self-checkout frustration at some point, but that’s no reason to take it out on the people working at the store. “Be nice to the staff member who’s nearby,” Leighton said. “They didn’t design the machines and so they aren’t the place to put any hostility about them.”Remember, they might be just as frustrated by the situation as you are. “Thank the attendant who likely had to come to your aid multiple times when you reached the ‘assistance needed’ lockout screen,” Farley said. Not Reading The Screen“Try to read the screens,” Smith urged. “It seems each system has a slightly different set of prompts and instructions.”Your lack of attention to the self-checkout process can inconvenience the other people waiting to pay for their items. “Read the screen prompts,” Farley echoed. “Repeatedly hitting the wrong button because you are only half paying attention will slow the entire line down.”Being Unprepared “Keep your eyes and ears open for the next available register,” Farley said. “Your distractedly looking at your phone while others wait behind you is inconsiderate.”Make sure you’re prepared to step forward once a machine becomes available, and use your previous experience to inform the process. Smith:“Be ready to bag your items and understand that the systems are terrible when it comes to light purchases such as lip balm, greeting cards or parsley,” Smith said. “Have your payment in an easy-to-reach pocket so that when you are finally finished scanning and bagging, there is no additional delay to pay.”Using Self-Checkout When It’s Not The Right Call“Take note of the situation as you decide whether to find a human cashier or self-checkout,” Smith said. “Look about you. Is it busy? Lunch hour? Very crowded? Next, consider how many items you are purchasing. The longer the list, the more likely it would be easier to use a real cashier lane.”The types of things you’re buying might inform your decision as well. “Opt for a cashier where available rather than self-checkout if you are purchasing multiple items that require tedious manual lookups ― fruits and vegetables, for example,” Farley said. “Ditto for using multiple coupons.”