I pretty much agree with what's been said. Here's what I would do:

First, Get rid of as much debt as possible. Where people often run into trouble is that they loose their source of income and then can't afford their bills, rent, mortgage, vehicle(s) payments, ect.

[Along the same lines, I would think about maybe speaking with a financial planner about how you could minimize your financial loss should things take a nosedive.]

Next, stockpile as much of the basics as possible (without putting yourself heavily into debt). Think about the things you might go through in a typical year. Obviously things like food and drink come to mind, but you really have to consider all the items you might go though. What would you do if you can't get toilet paper, shampoo, motor oil, diesel/petrol, batteries, replacement tools, seeds for planting/farming, ect? Some stuff can easily be substituted, others you pretty much either have it or you don't.

It's tough to say what to stock and what not to. Your personal needs and perceived standard of living are going to play a huge role. Plus, no matter how well you plan, stuff always happens that is out of your control.

As a final note, while it's a hotly debated topic, I would say it's worth it to have some small stock of precious metals, precious stones, and various currency on hand, if (and only if) your financial situation allows for it. You never know if you might have to stuff it in your pockets and use it to make a fresh start somewhere else.