A nifty feature within ShipIT is the Address book where you can store addresses for customers that you ship to on a regular basis.
To create common addresses within the address book in ShipIT select
Settings > Address book > Add new
Enter in their details and press Save.
When you create an order manually, you can populate details by using addresses from the Address book select
Ship > New Order
In lookup customer/address start typing the persons name
Once you have found the name you want to use press Use and the contact and address details will be auto populated.