Okay, this isn't technically makeup, but since it's still in the beauty genre I thought it was relevant. Hair conditioner and hair masks can also be used as shaving cream. I realize that it doesn't foam or even lather really, but it does create a smooth, slippery surface that helps prevent nicks and scrapes from razor blades.
However, something to keep in mind is that conditioner is a lot heavier than shaving cream — so you've really got to clean out the blades of your razor well to ensure that no oily residue remains for your next shave. For more ideas to get the most from your makeup, click here.