this is how i would do it if i am 20 again.
1. mortage, buy your own roof, and paid it off ASAP.
2. get an IP, create some cash flow so you dont have to depend on your job.
3. then you start to stack some metal or get some toys.
4. create more cash flow (property, shares).
5. use the cash flow generated to stack metal, dont waste it on toys/girls/casino/wife/kids.
6. go to 4. and repeat.
the shtf day is unknown, and this can go on forever, as long as all the market participant can benefit from it. so why not make it to your advantages as well.
i stack because i want my wealth out from the banking system (20%-30% allocation), not because of the SHTF.