Lost in Schlock is a blog by Tim Shrum, who creates props, monsters, and costumes for super low-budget films. The site has been around for awhile, and is chock full of tutorials and guides for all manner of objects. It is geared to the DIY crowd, so almost any prop shop can pull off the projects. I found some great tutorials on how to make Monster Mud, low budget fake heads, and molded gelatin prosthetics. I also found this old video with Leonard Nimoy about making spaceship models out of junk, which I swear I saw as a kid.