Mandatory Session Fee

Is there a way to add a session fee to the order when someone is purchasing digital downloads (or even prints) if they didn't set up a booking on the calendar?

Also, in a second question, if they DID and it took a 50% deposit, how do I automate the 2nd half when they place the product order?

1. For after shoot orders, on your price list create a new product group and make it mandatory before they can order any prints or downloads. In the new product group create a new product "other" IE sitting fee $xx.xx

2. As far as I know automated collection of sitting fee is not possible, you need to create a invoice from the sitting/booking order.

#1 above will be your best best.