If you are a leader and can assemble an army of helpers…
Contract with the management of your local fairgrounds or stadium to do cleanup after a major event. Recruit as many people as possible to help you. Be sure to communicate all the details to those people who will help you in advance. The day of the event, break your “troops” into groups, assign certain areas of the stadium to each group. Provide each person a trash bag. Be sure to be encouraging and thank everyone for helping you!