As I'm currently in the middle of a project after not having done anything for a while, I highly recommend signing up with RQA and piggybacking their jobs with your shopping routes.
While their one-off consumer pick up gigs are borderline not worth it, when there is a recall/quality control project, especially with the big box stores, you can bank some serious coin for easy work.
They definitely have some IT quirks, but their office staff is responsive, supportive and super friendly. They even called me from the office on Easter Sunday while I was out working to help set up some additional locations I had emailed about.
There is currently a covert recall for refrigerated pet food. I knocked out 15 locations from the first wave in one day at $20 per + 30¢ a mile, with each stop taking no more than 10 minutes. I purchased product to be destroyed at 6 of those, and that added maybe another 10 minutes admin time per location. And of course I peppered the route with gas stations to keep me rolling on Big Oil's dime.
Saturday I have a big loop to do three remote locations, so I switched to their $20/hr payment (they cover drive time) + the mileage fee. Filled in the map with 17 gas stations, ending with a $50 lighting audit, making for a very lucrative day.
Have synthesizers, will travel...