So you know these razors? The ones with the replacement blades that cost an OBSCENE amount of money?
Well I'm about to save you all of that obscene money.
Next time you shave, take your razor back to your room.
Find a pair of jeans -- any pair, it doesn't matter if they're old or new. Make the jean leg straight and flat, either by putting it on a table or your bed.
Now take your razor and "shave" your pants leg.
20 times in one direction, and then another 20 times in the other direction. I promise: It won't ruin your jeans.
Just like this guy here.
You can do it on any piece of jean, really.
According to Lifehacker, "The threads of the jeans run in a diagonal so switching directions allows for a balanced approach to fine tuning the blade's edge."