My sign, your sign? Everyone comes up with a unique sign for them specifically, sitting on the ground is easiest. Start with saying “my sign your sign” while patting your legs once for each syllable. Doing it correctly will sound like “we will rock you”. Then after that it’s easy, no words. If i am starting everyone does two pats and then instantly i do my own sign and then everyone does two more and then i do someone else’s sign, then they do the same, two pats and their own sign and then someone else’s sign. Continue till there are only about 5 people left, easy way to eliminate large groups into team leaders.