Start by painting a rough square onto the front of each black bag using white acrylic paint and Claudine Hellmuth's brushes. Allow the paint to dry. Using black StazOn ink, Claudine's Halloween clear stamps, and an acrylic block, stamp various designs onto the white areas. When you do this, keep in mind you will want to "unfold" the bottom of the bag (just hold it while you stamp with the other hand), otherwise you won't get a clear stamped image because of the bump on the opposite side.
Glue some various strips of torn vintage text onto the bags as you like, and then add some torn strips of numbers tape as well. Place purple tissue and kraft tissue into each bag along with your Halloween gift.