I suppose it would be mostly practical skills, cooking, fixing things. Usually had to be done by people themselves.
Maybe also mental things like navigating (with or without paper map) and remembering their daily and weekly agendas.
What other things would be a big difference with the people today?
Photo retouching as a physical trade. Colour photography and instant development killed the art of retouching black and white photos almost from one day to the next, because nobody could retouch colour photos and nobody wanted to pay for retouching black and white photos anymore, when Polaroids were easy to reshoot. My grandparents did it, but had to close the shop in the 1980s. I still have a few of their pens, but most of it ended up in a museum.
50 years ago was in the 1970s. I actually think more skills were lost just in the 20 years prior to that than after. This is due to mass production and plastic, which created the consumer products since the 1960s. Prior to that, you’d actually consider all products (except food) to be a purchase for life.