Binder Clip Organization
Use binder clips on your desk as cable organizers.
Use your drill press in reverse to make perfectly centered holes.
Need a non-slip grip on a tool? Try heat-shrink tubing.
Table Saw on the Fly
Lacking a proper table saw? You can improv one with a straightedge, such as a metal level, and some clamps.
Suck it Up
Dropped a small item on the floor? Put some pantyhose over your vacuum's tube... it will suck up the part, but won't eat it! [Photo from Instructables]
Clean and Cheap
Dollar store brass kitchen scrubbies can be used instead of expensive specialized solder tip cleaners; stick one in a container and dab away!