Always accompanied by a motion. Start with fists clenched and arms parallel to the ground out to the side of your body. Then, bring your fists together in front of your body at a 45 degree angle with the ground.
You will be making the motion of grabbing two extension cords and plugging them together, so that the music/fun can start.
"You guys ready to get this party started?"
"YEAH! PLUG IT IN!" (Use the motion described above!)