I just got done feeding horses and threw a couple of loops at the dummy...
Caught a few then asked hubby because like I said I am famous for doing it incorrectly!
Arm back, power comes from the shoulder and elbow, not the wrist. Same as mentioned above, coffee mug grip, momentum in the loop comes from drawing it back not pushing forward. Your hand should be palm down and fingertips up like if you were pushing on a wall when delivering. The loop should land fairly flat and open, the top strand hitting behind the head on the neck and causing the bottom strand to drop. If your loop comes down at an angle(like if the loop was a knife and the calf was a block of cheese) then you really have to make an ideal shot according to hubby which is how he throws but makes it work.
I DON'T LEAD 'EM AND FEED 'EM, I RIDE 'EM AND SLIDE 'EM.