First Aid and Basic Emergency Medical Care: Knowing how to stabilize a broken limb pending proper care, how to reduce or stop traumatic bleeding, how and when to apply sutures to a wound, etc. If you’re really inclined, you could go all the way and become a medic, a practicing nurse, or a doctor or surgeon. In general, medical training and knowhow are always in demand after a disaster or major catastrophe. There are never enough doctors or medics when you need them, so by developing some of those skills now, you can ensure that you’ll have skills that are in high-demand if you ever have need of them.
Mechanical Knowledge: Know how things work, how they are taken apart, and how to put them back together or repair them with whatever you have on hand. Learn how to repair generators, farm equipment, even cars (they’ll be around for a while, even in the case of most super horrid events).
Gunsmithing, Gun Repair and Ammunition Loading: take a moment to think about how many gunsmiths you know. Think about the number of people you know who own guns and various other firearms, and think about how many firearms are going to be in use in a post-SHTF situation. While you don’t necessarily need to turn full arms-dealer, being able to repair various guns and maybe reload some ammunition would be useful skills to have.
Weaving, Tailoring, Sewing and Mending: These skills are on the more homely side of things, don’t let that fool you. Clothing wears out over time, especially when worn for hard labor, and everyone appreciates a good pair of socks. Holes will need patched, socks will need darned, and eventually new clothing will need to be made.
Butchering Animals: This might take a little while to show its merit, but if you’ve got the guts and knowledge to properly slaughter and butcher a variety of animals for consumption, demand for your skills will gradually return and rise as society starts to normalize. Even during the hardest of times, if you can find work as a butcher it is usually sufficient to allow you to keep food on the table, as you can at least trade your skills as a butcher for a suitable share of the meat.
Growing and Preserving food: When was the last time you even saw food growing in a garden or an open field? This is truly one of the most important skills that there is. Not very many people even grow a garden in this country anymore. Where would you get food if not from the grocery store? Learn how to grow fruits and vegetables now and you will have a skill that absolutely everyone will want to know…