Research the average price for whatever you are shopping for online. Beware of scam artists who offer much lower prices as away to entice shoppers and perhaps lower their guard.
Don't let anyone rush you. Many online fraudsters will insist that the sale must happen immediately. This is often a way to force the shopper to decide without time to think about risks.
Be on the lookout for "Scammer Grammar." Red flags should go up if you see misspellings, words used incorrectly or language mistakes not typically made by those fluent in English. Also beware of any seller that refuses to speak with you on the phone.
Don't shop online from a public computer or over a Wi-Fi connection. This could lead to the loss of valuable personal information, including credit card numbers.
If you get an email asking you to "update your account," don't take the bait. This is a common way to get users to give personal and account information to scam artists.
Spice up your passwords. No words form the dictionary (or spelled backwards). Use letters, numbers and symbols to make them more protective.