Cell phone companies give you a free phone because they know they'll profit off the plan they sell you. Razor manufacturers are no different. They sell razors for a nominal fee and then make money off the disposable blades, and if you've replaced your blade lately, you know just how expensive they can be. But you don't need to replace your blade each time you shave -- far from it. In fact, there are a few simple steps you can take that will help your razor blade last longer -- and save you money.

A razor blade should glide across your skin, especially when you're going with the grain of your hair. If your razor feels likes it's pulling, that probably means it's dull and should be replaced [source: Gall]. A dull blade can cause irritation or a rash, or it could leave you with nicks and cuts [source: WebMD].

There's no set timeframe that dictates how often you should replace your blade because many different factors affect how long it will last. It really depends on how often you shave, how large of an area you're shaving and how thick your hair is. The key to switching out your blade less frequently is simply taking good care of it [source: WebMD]. Make sure you rinse the blade with hot water after every use to get rid of any hairs or shaving cream in the blade. Once it's clean, let it air dry to prevent it from rusting [source: Vivot]. If you ever find rust on your blade, you should replace it immediately. For more tips on shaving, see the links on the next page.