One important consideration is the bug out mode. Are you leaving on foot, via vehicle, or some other means. There is a big difference between what you can carry on your back compared to what you can stuff in your car....

I like to start with my backpack, which contains essentials, not the convenience items some seem to crave. Basically this means water, and equipment such that one can camp, sleep, fix something closely resembling food, and walk some more. Backpacking and hiking experience and gear comes in handy here.

If possible, my backpack, fully loaded and ready for a walk, is thrown in a handy vehicle which is then supplemented with tools, memorabilia, important documents, more water and chow, pets, etc - whatever is personally significant and necessary for the crisis at hand - your behavior will be different if you are contending with a fast approaching fire versus evacuation before the pending arrival of a significant hurricane or similar storm.

Above all, one must be rational and flexible. By their very nature, emergencies are always somewhat unpredictable.

More and more, i tend to include the means to recharge my electronics - anything from power banks to small solar panels to various adapters. I want to keep my phone and lights up and running, especially my headlamp. Sometimes handheld, it is far and away the best source of illumination, in either emergency or non-emergency situations. For that matter, the "phone" is far more than just a phone for most of us.