Background
I volunteer as an apartment group leader at my apartment complex. Every Monday, I'm in charge of organizing an activity (up to $20) for my fellow roommates and neighbors.
Recently, we had an ice-cream social (get to know the new people at the apartments). We ran out of ice-cream for people who arrived later, after everyone had finished eating and started mingling. Portion sizes weren't regulated, so most people probably took seconds.
Question
In these situations (where I'm given a limited budget and resources), how should I handle guests who arrive late and miss out on whatever was being offered to those who arrived on time/earlier? I don't know what to do or tell them - after all, I want them to come the next time something is organised. I need to make them aware, in a nice way, it's their own fault they didn't get anything and if they want what we had they need to arrive earlier the next time.
Let me know if I need to get more specific.