Cyber Monday (Nov. 26) is prime time for online shopping — in 2017, e-commerce spending on the holiday climbed to $3.36 billion. Thousands of deals and discounts are right around the corner, but to maximize your saving, here are six mistakes to avoid, and what to do instead.

Don't shop without doing your research

Prep is an important strategy when there are this many sales happening. Scope out top advertised deals or coupons beforehand at your favorite retailers or check out a site like Best Black Friday, which has a pretty comprehensive listing. For Amazon shopping in particular, Phil Dengler, head of editorial and content marketing for Best Black Friday, recommends checking out price tracker CamelCamelCamel to compare and make sure you're actually getting a good deal. "Amazon is huge when it comes to Cyber Monday, and there is no better resource than CamelCamelCamel for quick historical price comparisons," Dengler tells CNBC Make It.

Don't forget to update your store accounts

"Many items sell out faster on Cyber Monday than on Black Friday, so you have to be quick for the top deals," Dengler says. "With Cyber Monday, you are competing with the entire country online." That's why it's critical to confirm that the personal and payment info on all your online accounts is up to date. Even typing in a credit card number or shipping address could slow you down enough to miss the hottest limited offers. For example, "Amazon's lighting deals sell out extremely quickly," Dengler says. "The top TV deals are often gone within five minutes, so every minute counts."

Avoid impulse shopping

Just like Santa, make a list and check it twice...and then don't veer from it. Impulse shopping can be an easy trap to fall into when there are dozens of discounts happening. "You should make a list of all of the items you are going to purchase on Black Friday, be it in-store or online," he advises. "After making your list and budget, you should stick to it. "While there is a chance you may still buy on impulse, having a physical list next to you while shopping will make it easier to stick to your budget."

Don't miss out on credit card rewards

When choosing between paying with a debit card or credit card, Dengler recommends going with the latter. If you don't, you're losing out on easy ways to get cash back, airline miles or other perks. "If you are shopping online, you are probably already using a credit card, so you should be at least using one that offers cash back or other incentives," Dengler says.

Don't pay for shipping

"Paying for shipping is a huge mistake on Cyber Monday," Dengler says. Many retailers offer free shipping during the holiday season, he points out. Target, for example, is offering free, two-day shipping with no minimum through Dec. 22, and Best Buy is offering free standard shipping with no minimum purchase. Amazon Prime also offers free, two-day shipping on eligible items to its members, so Cyber Monday is the perfect time to consider signing up for a 30-day free Prime trial. For everyone else, it's offering standard shipping with no minimum purchase amount for a limited time. Plus, a Prime trial will also likely yield special deals exclusive to Prime members. "Last year, Amazon offered exclusive deals to Prime members only on Cyber Monday," Dengler says. "It is likely it does the same for 2018."

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