How to create a new delivery method
You can add a new delivery method by clicking on
Your Name > Account Settings and scrolling down to Delivery Methods.
Just below the header, you'll click on 'Add New Delivery Method':

Custom Shipping allows you to create a custom shipping cost for each invoice. This means that before you can collect a payment from a customer, you will first be required to update their shipping cost via the
Edit Order button.
Flat Shipping will allow you to set a flat rate, which any of your customers on that shipping method will be charged.
Flat Shipping / Live Shipping Cost will allow you to charge your customers a flat rate, but the cost to you will be adjusted dynamically using ShipStation.
Live Shipping / Live Shipping Cost will allow you to import live shipping rates from ShipStation, so that you may charge your customers a dynamic price that matches the cost of the shipping from the service you used. This delivery method works best for orders that are sent through FedEx, USPS, UPS, or any other carrier service.
NOTE: If your customers are set up with a dynamic shipping method (Custom or Live pricing), then you will be required to update their shipping cost on their orders before you can collect payment for that order. This includes customers on all payment terms, including Pre-Pay.
How Delivery Methods are included in Invoice Emails
If you assign a delivery type to your Delivery Method, your invoice emails will reference how the delivery will occur.
To assign a Type, visit Settings > Delivery > Delivery Methods
Once assigned, your Invoice emails' delivery section will be customized for each delivery method:
Pickup 👇
Hand delivered 👇
Shipped via carrier 👇
Please note: If you do not set a Delivery Type, the invoice email will default to the Shipped with carrier setting.