I would often do "dummy service". That is, I would show up only to pretend to preach. I would walk back from the Kingdumb Hell (about a mile) and call that an hour of service. Or I would find a quiet street and take a walk there with a bag of literature when I know it's going to be dead, and call that an hour of service so I would be regular (ultimately I totally gave up on that; I then shredded every single one of my magazines).
One time we went into a bookstore with pockets full of tracts to place with other customers. Instead of doing that, I would stay in areas with no traffic. I browsed through the books instead, and ultimately returned to buy the book. I placed nothing in 2 hours, but I still counted that as 2 hours of service. It was my only service that month.
My favorite is the drive across town. We spend half an hour fighting traffic, red lights, and hunting for the street and then the house. And we get to the door and lo and behold! No one is home! And that's the only service I do all month. Zero placements, and I still placed a time slip in the box (nowadays, I have better things to do than add my one more slip toward their celebration of cresting 7 million. It will happen soon enough; I don't feel like speeding it up any).