A Perfect Twist

Step 3 Secure the wire so you can begin twisting

Once you have closed the chuck around the wire, you might want to give it a good tug to see if it will pull out.  Mine come out about 20% of the time, even when I have checked and double checked the placement.
Insert the phillip head screw driver between the two wire and move it down to the looped end (where the wire was doubled over).  Pull the wire taut so that it will twist evenly when the drill is started.