The container for your floral arrangement is critical to the overall proportion of the arrangement. Your arrangement should be 2 to 2.5 times the height of your container. Also, try thinking outside of the "container box" and consider using something off the beaten path (ie, a tin can, watering can, hat box, or like pictured a mint julep cup). Basically, anything that can hold the foam is considered a container. The most important elements when working with proportion are the scale of the flowers in relationship to the container and the scale of the arrangement in relation to its purpose and placement. Use your imagination to make an impact with your arrangement. With a floral arrangement, it's better to go overboard than to be unnoticed.