If Amazon Prime Day has you feeling overwhelmed, you're not alone. But planning ahead could help: Shopping experts say you can start to narrow down your shopping list now so you don't miss a great deal or, worse, end up with a ton of returns. Prime Day, which starts on July 15 and runs two days this year, offers members (and members only) huge discounts on a wide variety of products. Almost eight out of 10 Prime members in the U.S. are planning to shop on Prime Day this year, up from 63% last year, according to a new study from Profitero. But some deals are better than others, especially if you're looking to snap up a big-ticket item. To help you narrow down your shopping list and snag the best deals, here are the five types of products that experts believe will rack up the deepest discounts during Prime Day.

Amazon Services

Amazon's own products get a major push on Prime Day, so if you've been tempted to subscribe to some of its services, including Amazon Music and Kindle Unlimited, now is the time to do it. Amazon is already offering a 66% discount off the cost of audiobook service Audible. Prime members can get their first three months for $4.95 a month. For groceries, Amazon is offering $10 off Prime Pantry orders of $40 or more. And if Prime members spend at least $10 at a Whole Foods store or through Prime Now (which partners with the grocery retailer) from now through July 16, they'll receive a $10 credit to use on Amazon for Prime Day purchases. "Amazon has a lot of control over the pricing of their own brands, and is very well known to be willing to take a short-term loss to gain market share," Rebecca Lehmann of Brad's Deals tells CNBC Make It. "In the past we've seen Amazon use Prime Day to drive awareness and gain exposure for these brands, and I think we are going to see even more of that this year."

Amazon Electronics

If you've been eyeing an Alexa-enabled device, such as the Echo, hold out for Prime Day on Monday. "Last year's Prime Day deal for this device was $64.99," Regina Conway, consumer expert for deal site Slickdeals, tells CNBC Make It. "This is something we would predict will likely continue to have price drops around Prime Day." Typically it retails for $100. Ring video doorbells are already on sale for $169, and if you buy one, Amazon will throw in an Echo Dot for free. The bundle is usually $299, so you're saving $130. Beyond its Echo line of home products, experts also predict other Amazon electronics will see deep discounts, including the Fire TV stick and the Kindle Paperwhite. Amazon also collaborates with TV manufacturers, so expect these TVs to be on sale. "I think we're going to see some big Prime Day discounts with a focus on the 55" Fire Smart TV model," Lehmann says. Last year, the Prime Day deal around the Toshiba 50" 4K Amazon Fire Smart TV, which dropped from $399 to $290, proved popular. "It was one of the lowest prices we'd seen for a 50" Smart TV and this particular TV had never been discounted before," Lehmann says. In late June, Amazon launched an update to the Fire Smart TV line with the 55" Toshiba including Dolby Vision for dynamic HDR. Lehmann says the timing is "no accident."

Name-brand electronics and other accessories

"While Amazon has focused some of their biggest discounts on their own electronic devices, there are plenty of deals to be had," Sara Skirboll, shopping and trends expert at RetailMeNot, tells CNBC Make It. Headphones will again be big, Tiara Rea-Palmer, head of retail at CouponFollow, tells CNBC Make It. That includes noise-cancelling, earbuds and even expensive brands like Beats, which have had discounts as high as 55% off in past years. Be on the lookout for Apple products as well, since Amazon is now an authorized Apple retailer. The Apple Watch 4 is already on sale for $399, down from $429. And Apple AirPods with Wireless Charging Case are $180, $20 off the retail price. Lehmann says she expects to see iPad discounts during Prime Day as well. While electronics across the board will see big discounts during Prime Day, Skirboll says that consumers need to carefully check prices. "Some of the biggest deals of the year from the retail industry on things like consumer electronics are still concentrated on Black Friday," she says. Unless you see a really great price on an item you need now, you might save more by holding out until November for things like TVs, laptops and cameras.

Gaming

Video game bundles will be another area where shoppers can save big, Rea-Palmer says. "Although you probably won't find a sale on a Nintendo Switch, you can likely save with a Switch bundle on Prime Day," she says. Consumers should watch for bundle gaming deals for Nintendo, Xbox and PS4. But before you buy, make sure you're going to use all the components of the bundle, which typically include games, controllers or cases. Otherwise, it may not be a good value for you. Gaming accessories will also be big, Conway says. For example, she expects the price on the ViewSonic Elite XG350R-C 35" UltraWide Curved Gaming Monitor to drop by $140 during Prime Day, from $699.99 to $559.99.

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