I found this tip on http://www.everylastpenny.com/

Extend the Life of Your Razor Blades

Everybody can agree that razor blade replacement cartridges are very expensive, and with the introduction of 3, 4, and even 5 blade razors, the prices have gone up dramatically.

This money-saving tip is so simple, but you can easily make your razor
blades last at least twice as long as usual. In a nutshell, all you
have to do is thoroughly dry your razor blade after each use and before
storing it away.

But why does such a simple trick make your blade last so much
longer? The simple answer is that it helps reduce microscopic rusting
at the edge of the blade. It seems counter-intuitive, but it's not
shaving with the razor that causes the dulling effect, it is
microscopic edge rusting that is mostly to blame.

I have found that the best way to dry the razor is to blast
the residual water off by blowing air through a drinking straw then
dabbing off the remaining droplets using a towel or tissue. If you
don't want to use the drinking straw method, you can just shake the
water off, but I have found that often leaves small pools of water at
the edges of the blade.

Every time you use your razor, dry it thoroughly and you will find that they will last twice or three times as long as usual.

I'm not the only one that thinks this is a good idea. There is some more in formation here, here, and here.
The best way to prove to yourself that it actually works is to take
note of how many shaves you get when you don't use the technique vs.
how many shaves you get when you do. You will be pleasantly surprised!

Happy shaving, and happy saving!