This is most likely one of those “Duh” areas, however for the main couple months that I sold pot, I didn’t know how to roll a sack. It’s good way to package your pot.
To start with take a sandwich baggie and place the eighth at the base of the sack with the buds lined up in a line to cover the whole base of the sack, then just fold the sack over the buds and roll the sack firmly as if it were a joint. Lick the top fold and force it around the sack to make a barrel. A perfect sack can be held with two fingers toward one side and will stay straight.