Some carriers allow you to set an insurance option on consignments. The cover provided will vary with the carrier so check your agreement.
Go to Settings ⇒ Carriers in ReadyToShip and click on the carrier. If they offer insurance there will be options like this:
Some carriers will also allow you to override these defaults on a particular order. If this option is available a check box will appear in the Order Options: area when you click on an order and view the details.