Separate orders cannot be combined. If you would like to save on shipping, make sure you place a single order for all of the products you would like shipped together.
Subscription and add-to-next items that are processed on the same day using the same payment method and the same shipping address are automatically combined by our system and will ship as one single order (subject to maximum dimensions and weight allowed by carrier). Make sure that the address listed under Shipping in your Subscription Manager is correct, as it overrides the default shipping address for normal store orders. For more information, visit the Subscription FAQ.