I usually make friends with those around me and the store personnel if I can. That way when line jumpers show up, I speak up and let others know that they are there and usually everyone closes ranks and the store staff usually directs them to the back of the line. One year a 20something tried to jump by saying his mom was already in the store and he had her money. I even spoke to someone on the phone that claimed to be her but still refused to let him cut.