The WorkCloud Safe Custody add-on works on the same basis of general "Related Matter" therefore establishing the link between the client file/current matter to the Deed Packet.   

To open a new Deed Packet, firstly open up the client matter and select the down arrow next to the words related matter

From this next screen select +Add New

Complete the new matter form as per normal completing the party and packet details as marked and hit create matter.

*** Note if there is no existing matter you can still open up a Deed Packet as you would a normal unrelated matter, however, we stress that wherever possible, use the related matter feature of Actionstep