Split-coil knobs!

 This is a D.I.Y. way to turn your guitar's unused tone pots into split-coil pots for humbuckers!
 All you have to do is to remove the tone capacitors, resolder your guitar's tone pots and there you go! Here's a schematic of the circuit for one humbucker:

 The above schematic is a modified version of Seymour Duncan(R) 's schematic and is for reference only. It must not be used for commercial purposes.