Having a problem with setting up shipping - hoping you guys can help. Have different products that all ship different rates and finding it tough to combine shipping for multiple items.

Normally we sell item A with $6 ship & B with $2 ship. How can I set it up so that if a customer buys both A & B that they are charged $6 (B ships free) OR can it be set up that they are charged $7 (B ships for $1).

Thanks.