Get good with your religion. Face it, the whole thing to doomsday is that most people will die, if not all. You are not the focal character in a book or movie, so you’re as likely to die as anyone, just from bad luck. No matter how good your shelter, if you are at Ground Zero for the bomb or the meteor, it’s all over. Adjust.
Next, try to avoid natural disaster areas. Yes, that’s me laughing like the Wicked Witch of the East. It’s not easy to find areas that are not subject to —
• earthquake (remember the New Madrid quake or the Helena, Montana quake: these are hard to get away from),
— let alone supervolcanoes or snap glaciation, and nowhere is safe from comets and asteroids. But really, living in some place that goes to the sandbags every few years is not my idea of a good place anyway.
Mind you, you have to have a job or two in the place. If you just have to live in a disaster-prone area, you can practice prepping for doomsday by prepping for the more likely disaster every few years. Don’t live in Tornado Alley without a reinforced storm cellar. It’s your first level of doomsday shelter, right?