Go to large shopping mall with a cinema within walking distance. Go to the cinema and get the largest popcorn bucket available, just the bucket no popcorn. Make fake base and glue it 1 inch from top of bucket. Put a handful of popcorn on the base so it appears you have a full bucket of popcorn, when really you have a hollow popcorn bucket. Now cut a slit in the hollow popcorn bucket and go to any store. You can put as much as you can fit in there and they will assume its just popcorn.