I have done a lot of different things.
Sometimes I have walked home with a bike in each hand.
Sometimes I have strapped the other bike to the rack on the back of my bike.
Sometimes I have moved the bike I want to pick up to another location where someone else is not likely to see it and pick it up. I often do this if I see more than one thing I want to pick up.
I have asked the people living there if I can put a lawnmower out of sight in their yard. I came back to get it with the car.
Well, if I had a car I wouldn't be out picking junk bikes!
Yeah, I have done those things .... and it took a lot of time and energy, which is what i said. I made it work, but it took dedication .... and back all those years ago i could miss half a night's sleep and still function.
A bike makes a good -two-wheeled cart---one can hang all sorts of stuff off it. However, it can be hard to push and balance .... but back then i'd push an overloaded bike a few miles rather than lose a couple good finds.