How to short society is a subpoint in the book The Ministry for the Future by Kim Stanley Robinson. In it, one of the main characters, the head of the UN's Ministry for the Future, is meeting with big banks, and while doing so, internally, she wonders how to short society. In it, she doesn't figure it out. However, I believe that I have some methods for it myself.
There are some problems and definitions and stuff that need to be described here first though. The first problem is that, in the event of societies collapse, conventional money would be worthless. The second, is finding someone willing to make that short with you, as if everyone knows that society is soon to be doomed, nobody would be willing to help you short it, as they all would want to! The third problem is that the market can stay irrational longer than you can stay solvent. If you KNOW that society will eventually crumble, it may take too long for you to be able to hold out and the collateral required will be too much, and you'll end up bankrupt. The fourth thing I would like to mention, is how I am treating a "short" here. Not every method I say will be a literal financial short, but they all will do the same functional thing, which is immediate money payed back later, and putting a downward force on the thing being shorted.
Now with the exposition finished, I will detail the methods.
This is a fairly straightforward method, as all it is, is shorting a high-value, normally up stock (such as the S&P500), and hoping that society, and the stock, crashes before the collateral you have to put up wipes you out. It relies on primarily luck, and probably some sort of inside knowledge or something as to when society will actually collapse.
This tactic is simply spending money on prepping material. It isn't technically a short, but I believe it functions close enough, as the key part is the downward force on society, which prepping does do, as it acts as someone saying "We're doomed", which would be demoralizing, and as such, contribute to unrest.
This method is somewhat complex. It hinges on the fact that disinformation can be both profitable, and apply a downward force on society. The strategy is to create a fake persona, which says a lot of disinformation, in an attempt to get followers and donations, and then drop off the face of the planet, as the followers get more rabid and wondering as to what happened to the person they were following. This both has a money now aspect, and a downward force, making it, I believe, one of the best strategies.