1. Be suspicious of overdoing it. It is much easier to overspend when you find yourself shopping online. You begin to rationalize that you can spend more money for those shoes because you saved money on gas and the food you would have gotten should you went to the mall, as an example. Give yourself a restriction and stay with it.
2. Read customer testimonials before you buy anything. People are more than pleased to complain about bad service online, so try to find sites and testimonials which are terrible so that you know what you're getting into. You should take bad reviews having a grain of salt, but if you see many, you know you will find a problem.
3. A good online shopping tip to remember is always to leave feedback after buying from a source you've never bought from before. This will help the both of you because you'll remember whether you've had a good experience from them, and they can also obtain a reputation as a seller.
4. Make sure that you're entering your payment details on a secure site. Search for "https://" within the URL in the site that you're seeking to buy something from. If you don't see that or no indication of any website security, then it's probably a good idea not to trust those people along with your account information.
5. Be careful which sites you patronize. It is difficult to find out which are on the up and up and which can be not, but there are a few clues. If the address does not make sense or the design seems off, go to a different site. Additionally, if a bunch of pop-up windows begin appearing, close them out and move on.