However, by far your best survival 'tool' is your brain! If you develop and hone your life-skills, that's worth a whole lot more than kit alone. The mental stamina; the knowledge; and the confidence that you can survive, keeps your morale higher than it otherwise would be, which is also a good thing, as one's health stays stronger when we aren't feeling down or stressed and worried.
Maybe I've stated the obvious, but not maybe to some; but we do need to focus on what really matters, though giving thought to equipment too - but just don't be consumed by it! Talk to Chris Caine, who lived life on the road for 20yrs, with very little by way of equipment. It was mainly a mental exercise! A lovely guy, and very down to earth. I have his first rate 'Companion' knife with 'Survival' sheath. It's really about the best combination of practical application, carry size and weight, as well as a 'real' multi-use tool. It's nothing like the cost of some hand-made 'designer' knives, but does make them look like over-priced toys by comparison. This would be my main knife WTSHTF, plus a few other items which I won't go into now. Don't get me wrong, I LOVE my tools and equipment, it's just that the adult in me knows that it's pandering to childhood dreams, by and large (go on, admit it!).
Oh, and I don't have any business connection with Chris Caine or his knife, or Staniforth, the Sheffield company that make them for him (actually 'Lofty's design, according to Chris - you know, John Wiseman, the 26-year service in the SAS. They know each orther well, and Lofty asked Chris to get the knife made, handing him the design).
Ta ta for now folks!