From wireless headphones to S'well bottles, how to find the best deals on Amazon's hidden sale section

@itsjuliwilliams | Twenty20

Even if you consider yourself a pro at shopping on Amazon, there are still some surprising ways to save money beyond just Amazon Prime. Enter, Amazon Outlet, the Amazon sale rack that's hiding in plain sight.

Amazon Outlet is a section where sellers can move overstock or excess inventory. It's been on the e-commerce site for several years but is somewhat of a hidden, unknown gem.

"Think of it as an online Marshalls or TJ Maxx," Sara Skirboll, shopping and trends expert at RetailMeNot tells CNBC Make It.

The items that you'll find in Amazon Outlet span every category from beauty to home improvement. Indeed, it's a bit of a grab-bag, but Amazon must approve all the products that sellers move to the Outlet before they end up on the site.

That means you can count on everything in the Outlet being in new condition and having at least a three-star Amazon rating. (Items that are available on Subscribe and Save aren't eligible for Amazon Outlet.) But it takes some digging to get to the best items.

Some solid picks? We found a 64-ounce Swell bottle, which is typically $55, for just $45 on Amazon Outlet. There are even tech accessories under $20, like a pair of wireless earbuds with a four-star rating for just $11 or an AirPods carrying case for $7. Or if you're hosting guests, there are some deals on useful entertaining items, like a $7 wine tumbler.

The exact products in the Amazon Outlet change regularly, so here are some tips for scouring the Amazon Outlet:

Find off-season steals

Right after the holidays, check Amazon Outlet for discounted decorations or seasonal items, Skirboll suggests. For example, in the months following the holiday season you'll be able to find discounted seasonal decor, like Christmas ornaments. (You may want to avoid the last-season candy and food items, though, she says.)

To that end, you can also score last season's clothing styles for discounted prices on Amazon Outlet, she says. Right now, you can find ski jackets from name brands like Columbia, as well as outerwear for kids and ski goggles.

Search, don't scroll

If you don't really need to buy anything, browsing Amazon Outlet can be dangerous, because the low prices make otherwise unessential items seem more interesting. "So, go into your shopping experience on Amazon Outlet thoughtfully knowing what you need and what you're willing to pay, and get out of there," Skirboll says.

Stock up on gifts

Before Amazon was a massive online retailer, the site primarily sold books. Skirboll suggests looking for books to give as gifts on Amazon Outlet. From fashionable coffee table books to children's books, there's an eclectic range of almost 1,000 titles from $1.29 and up.

Do your homework

While Amazon does have close to everything, it's wise to quickly search and see if you can find products for a lower price at other retailers before you pull the trigger, Skirboll says. Other shopping sites may offer better shipping or have a better return policy, she says.

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