Don't ask employees to "check the back" for items
At many large grocery stores and big box chains, asking an employee to "check the back" for an item isn't necessarily an unreasonable request.
But, at Costco, there just isn't a "back."
"We don't have any additional storage from what you see on the shelves," a Costco employee told Reader's Digest. "If it's not there, don't ask us to check the 'back.' The 'back' doesn't exist."
You don't need a membership for everything
Standard Costco memberships go for $60 a year and can help customers rack up huge savings.
But you don't need a Costco membership to buy wine, get an eye exam, hit up the pharmacy, or grab a bite to eat at the food court.
If you need a flu or shingles shot, you can also show up with a signed immunization consent form and get it taken care of.
Simply tell the Costco employee manning the door what you're there for to enter, Eat This Not That recommends.
Start your hunt in the middle of the store
Business Insider's Kate Taylor reported that many Costco employees place the store's biggest bargains in the "center court" of the store.
You're better off skipping the more expensive displays at the store's entrance, and starting off somewhere in the middle.
There's a reason stuff gets moved around so much
The displays employees set up at Costco are far from static.
The chain touts the flux as a sort of "treasure hunt" — and they're right, in a sense.
Reader's Digest reported the nomadic products keep you scanning the shelves and buying more.
Pay close attention to the price tags
How can you tell if an item's been marked down? Easy — the price tag will end in $0.97. And if employees have marked the price tag with an asterisk, then it's not slated to be restocked.
Buying in bulk isn't always the way to go
At Costco, you can save money by buying items in bulk.
But you should avoid seeking out such deals for certain products, especially anything "best used when fresh," according to Eat This Not That.
Avoid making assumptions about employees
Want to avoid ticking off a Costco employee? Don't assume they're looking for a better job.
In a piece published in Refinery 29, former Costco employee Meghan DeMaria wrote that she loved working at the store and resented the implication that her job was "less important than any other job."
In a Reddit AMA, one anonymous Costco employee said that the store's "pay scale is awesome for the industry."
"Benefits are good, vacation is awesome after a few years, and they have a lot of employee-care type stuff," the employee wrote. "We have a lot of 15-25 year employees at my store."
The result is a large number of employees who stick around for the long haul.
"Even as a 10-year employee, I'm in the middle of the pack when it comes to average seniority," the anonymous employee wrote. "We made a name tag for an old-timer employee that said Employee since 1887. Took him a while to catch it."
Forget about using coupons
Sorry coupon-cutters, you're out of luck here.
Employees won't accept coupons at Costco. And you ought to leave any manufacturers' coupons at home too, according to Reader's Digest.
If you're looking for the best possible deals, just keep checking Costco's member-only savings updates.
Don't worry about missing a sale
Miss a sale? No problem. If the product you purchased goes on sale less than 30 days after you bought it, Eat This Not That reported that Costco "will pay you back the difference." No receipt required.
Costco has some unusual items up for sale
Costco isn't just a place to buy your standard groceries and everyday items.
Thinking about becoming a doomsday prepper? Costco's got you covered with massive emergency food kits — the cheapest one is $1,000.
Need a car? Look into Costco's auto program, which hooks you up with discounted vehicles from participating dealerships, Business Insider's Mark Matousek reported.
Costco even has a funeral category that sells caskets and urns in most states.
Basically, think out of the box when it comes to items you can buy at Costco. There's a good chance that they may sell whatever you have in mind.
Mondays and the end of the summer are key times to shop
When's the best time to make a Costco run?
Popsugar reported Monday and weekday mornings tend to be quiet.
In addition, the end of the summer is a great time to grab the outdoor furniture that's been marked down at the close of the season.
Are you a current or former Costco employee with a story to share? Email acain@businessinsider.com.