Daisy-chaining extension cords is a process for connecting two extension cords together when one extension cord isn't long enough. Daisy-chaining extension cords is fine when the cords are of a large-enough gauge to support the extra run, but can be limit the amount of power to the tool (and even be a fire hazard) when the gauge of extension cord is too small.
String out the two extension cords to be daisy-chained, so that there are no kinks in the cords.
Insert the male end of one cord into the female end of the second cord.
Align the two cords about a foot beneath the connection. Make a large loop with the two cords, then push the connection through the loop and tighten to make a loose knot.
Plug the male end of one extension cord into the power outlet.
Connect the tool to be used into the open female end of the daisy-chained extension cord.