I stir mine first, then shake. If manually I add a few BBs. I've not tried the jigsaw thing, just read it in the rag and thought it sounded pretty easy.
Once I've shaken mine I remove the lid, turn it upside down and use whatever is on it first. I cover the bottle with a black plastic lid from a 35mm film container, fits great. I don't own an airbrush so bottles and spray cans are what I use.