Cars picked up at outlying sidings were picked up by verbal orders of dispatcher or an agent. The industry would supply a legal document called a Shipping Order, either at the car or delivered to the local agent who would then make the waybill. The train crew might wait at the past or next station while the agent typed up the bill as the waybill usually followed with the car or nearly so. The waybill can be made out days ahead of the pick up, or after it.
Depending on the industry, it could be invoiced, pre-paid, or order-notified. Order-notified is where the receiver of the inbound car will need to go to the bank and pay for content and the shipping costs before the crew ever places the car where it could be unloaded. When things are paid for, then the car is re-spotted on the industry siding or team track.
If you ever get a chance to scan a SV blank or filled-out waybill, it would be interesting to see one posted here for any one to copy and use on their model railroad.
I forgot to add in the last message that when a waybill is folded vertically, one side shows all the origin information and the other side shows all the destination information and the conductor sitting at his desk in the caboose need not unfold all the bills to copy data onto his wheel report.
As cars are picked up, he added the new numbers to the bottom of the wheel list and as cars are set out, he records the destination code number. If it car is a Bad Order setout, he would note that on the information column as BO. He would also have to make several copies of a Bad order tap, nail it to both sides of car with reason of b/o, example “broken flange”. Another copy is taken or sent into the office so the car department is informed to fix the car. His total handle for the trip is the number of lines used on the “wheel”.
The caboose was the conductor’s office and had a full supply of paper forms used to inform all who need to know. He could even make a memo-waybill for proper car movement, while a legal waybill is made in the agency at the main terminal. But he would not do work that would put the agent out of business even although they were different crafts in the union.