When I lived with my parents, it was in a pretty high cost of living area, so I worked at a fast food place that paid I think $16/hour or something. After only a week or so later, I moved in temporarily with my sister in another city, and worked at another branch of the same fast food place. Because it was owned by the same franchising business (they own a ton of different restaurants throughout the Midwest), I was already in the system at my pay rate and they never changed it, so I was making more than the managers.
The GM also gets a big bonus if enough customers filled out the survey, so as incentive she said that for every 10 surveys we get customers to fill out in two weeks, we’ll get a $50 bonus. So every customer who came through the drive thru I’d write my name on the receipt and tell them that if they filled out the survey and mentioned me, I’d get $5. By being friendly, I’d get an extra $200 every paycheck. When I quit and moved back, she took forever to pay me the last bonus even though I texted her every day about it, so I never got that last one.
A couple other things I did:
If my sister or her friends came through, I’d list their food as an employee meal right before I cleared it from the screen so it would be free and no one would notice.
We had a promo where you could win a new Xbox by using the unique code on the cup, and someone specifically asked for one of those cups because they won a similar thing in the past. We had a stack of ~20 or so that we were about to throw away because they had Coke spilled on them, so I gave them the whole stack.
I saved a lot of the “no questions asked free taco sorry you’re upset” coupons when people used them and used them myself.