Sometimes you want to re-ship an order by creating a duplicate. This can easily be done by finding the original order in Order History, and click on the RMA link.
Once you reach the RMA page, change the mode to "Duplicate". You get to choose to change the original order id, for example you can add a -2 to the end of the order id. You can further edit the order to change the content or the address, place into a different queue, add notes, etc.
Once finished editing, you click on the "New Order" button and you will get a duplicate order ready for shipping. The order will be the same as if you used the "Add Order" to create a Manual order.