For those really, really hard-to-reach spots
Next time you need a 3-ft. long screwdriver or drill bit, try this simple trick. Buy a 3-ft. piece of 5/16-in. threaded rod ($1.50) and a 5/16-in. coupling nut ($1 per pair) from a hardware store or home center. Pound the hex end of a bit driver into the coupling nut, which is typically a hair smaller than the driver (squash the coupling nut in a vise if it’s too big). Screw the coupling nut onto the end of the threaded rod (saw off any unneeded length with a hacksaw), and chuck the rod into your drill. Stick a drill or screw bit into the driver for extended reach.
15 Revolutionary Techniques for Driving Screws