Gather your straws (don't forget to flex them out) and put them in the container. It's important that the straws have a tight fit so the jello stays in the straws. For this reason, a 1 liter carton may be better; you will probably get longer worms since there is a tighter fit. If you have a bigger container, a rubber band around the straws is helpful. Or you could just add more straws to fill the container.