I became aware of the world just as seasonal food availability was becoming a thing of the past—I remember significantly more seasonal variation, but only when I was pretty young—so this really stuck with me growing up. All those colorful jars lined up on shelves, all the gardening, all the boiling-of-jars, et c. All that work, and a can of the same thing was $0.29 at the store.
So I assume they all developed these super-similar habits for really great reasons. And since the ~1960s and earlier were just normally pretty similar to what a significant food shortage would probably look like now (at least in countries that will almost certainly be able to maintain adequate supplies of staples, like the US) it seems to me that might be a good first place to look. Stock up on canned veggies, worry less about the rest of it. Maybe get some chickens and plant some berry bushes (they also all loved keeping a line or two of berry bushes, and it seems like in their generations you just alway kept chickens, if you weren't smack in the middle of town)
I'm going to ramble a bit... I grew up on a farm in the actual middle of nowhere. It was a then-defunct, mid-size dairy. In it's heyday it had 300 head of Holstein being milked.
My mother, whose parents ran the dairy, and to a large extent my father, instilled this way of life on me at a young age. Growing up, we had a huge vegetable garden (they still maintain a 1/8 acre vegetable lot in their 70s, it's quite impressive, really -- and that's in addition to a 400 sq. ft. greenhouse I helped my father build and the rest of their lot that has fruit trees, berry bushes, etc.) but I was always in awe of the canning and the preserving. You grow all of this food but you only eat 20% of it fresh, canning and preserving the other 80%. But then, being so young I didn't realize that our meals consisted of vegetables/fruits that were canned or preserved years previously, of course. There was a strong communal aspect to it, too. We'd get oversupply from neighbors and/or give oversupply to neighbors.
Chickens, too. The farm had a coup. My parents had a coup (they gave it up in their late 60s -- my father grew tired of dealing with the foxes and skunks they attracted). It's something I want to do but where I live it's impossible. We're planning on a move where we can have a chicken coup and more space for growing food in general. I'd really like to preserve the heritage, as it were, and it's become more important as we start a family.
Also, I've dealt with corn and wheat weevils before. I actually did not realize that they also laid eggs on rice. I guess I assumed that it was "different" or whatever but thank you for highlighting that in other comments. I've got 50 lbs. of rice that I'm going to break down to smaller vacuum sealed bags this weekend. I've dealt with weevils at least a half of a dozen times in my past and it is not pleasant. I do not want a repeat of that mess, but especially where I live today.
So I assume they all developed these super-similar habits for really great reasons. And since the ~1960s and earlier were just normally pretty similar to what a significant food shortage would probably look like now (at least in countries that will almost certainly be able to maintain adequate supplies of staples, like the US) it seems to me that might be a good first place to look. Stock up on canned veggies, worry less about the rest of it. Maybe get some chickens and plant some berry bushes (they also all loved keeping a line or two of berry bushes, and it seems like in their generations you just alway kept chickens, if you weren't smack in the middle of town)