I hold an "8-hand" to my lips then "snap" my thumb and middle finger as I
bring the sign upward.
(Some people just touch the tip of their middle finger to their lips and then
move the hand up while twisting the hand to a palm forward position. Which
looks a lot like the LUCKY sign.)
Animation: delicious
American Sign Language University ™ ASL resources by Lifeprint.com © Dr. William Vicars