Collecting Cups
In music festival or venue that use reusable cups, you usually pay like 1$ for the cup refundable when you bring it . There’s always cups left everywhere that people are to trashed to bring back. Collect a couple, cash the refund and there you go: free drink.
Drank all day long for 5$ at Osheaga the last time I went.
Story credit: Reddit / sunforrest