When I was 17 I delivered pizzas, The way we worked the money was that every order's receipt that I delivered went into a box under the counter. I collected all the money and at the end of the night I turned in an amount of money equal to the sum of receipts in my box, what I had left over was tips. My bank was my rear left pocket and it wasn't uncommon for me to turn in $500+ at the end of the night. Sometimes if it was slow I would cancel out a stack of receipts and bring my bank down to under $100, but that wasn't often. Never worried about getting robbed.
Oh I almost forgot: the first receipt was the $100 in various denominations of bills and coin the boss would front you for making change, which brings me to a funny story. Myself and a guy named Mike were the first two delivery guys to ever work at this particular establishment, and were both hired on the day that the place started doing deliveries. Mike took the first delivery order for the business ever, I took the second, and the third, then delivered the Mike's order to the angry customers who hadn't received it, and the fourth: Mike hadn't come back after leaving with three pizzas and the $100 in change-making money. The boss was livid (and feeling kind of stupid). After about an hour and a half Mike shows back up at the shop. He had hit two pedestrians with his truck three blocks from the shop! He was tied up with the police all that time (this was 1998 before cell phones were common)! I left after a few months but Mike worked there delivering for 9 years. He delivered a pizza to my house (from a different shop) about 6 months ago and we did a little catching up.