Looking hard to find Mach 3 razors for $1.65 a blade (usually they're at least $2), I researched ways to increase the usage span as I was throwing a blade away after every 4 shaves. Now I get 12 shaves. Here are the 3 things I've learned to do:
1. I never let my beard grow more than one day so now I'm religiously shaving every other day.
2. I clean all the stubble from the blade so as not to block the lubricating strip.
3. I towel-dry the blade and keep it outside the shower (I shave in the shower) when not in use.
Now I'm getting twelve shaves per blade.