I like the idea of counting the wrapped utensils.
A couple years back we were hired to serve for 160 people at a department bbq where I have my weekday job. People from other departments heard there was free bbq and started lining up. We ended up feeding almost 300 people. The organizers ran to the store mid-meal to get more food for us to cook. But the sad thing is people in line were getting mad at us when food was running out. Talk about lessons learned.