I just found this site that allows you to make templates for Gift boxes, Polygon-shaped boxes, Envelopes, Card Boxes, Bags, Shadow Box Frames, Cones, Milk Cartons, Counter Display Boxes, Pillow Boxes and Decorative Stars. What makes this site special is that the templates are all dynamic and that you can customise almost all the dimensions to make truly personalised containers.
Kay from Clever Someday shows your here on her blog how to use the with your electronic cutting machine to speed up the creative process.
Hope you find these as useful as I did.