Since ammo is still so expensive lately, I am thinking about packing a Dillon 650 in my BOB instead. That way I'm set. LOL.
In all seriousness, I actually started going through my bags over vacation to update/refresh them as well so it's fresh in my mind. I'd agree though the one thing you have to figure out first is what the purpose is. Are you putting together a 3 day kit to hike from your house to <somewhere>? Are you looking for a "get home" bag to have in case you need to hike it from your office to your house some day? Winter car kit? All of the above? Lots and lots of threads here and on many other forums with suggestions and ideas.
As with all of these SHTF scenarios though, start with the most likely problems you expect to face. Do you work in an office somewhere? Do you have a good kit in your car you could use in case you need to get home and have to walk? Did you remember warm clothes and comfortable shoes?
Maybe next - if your place is hit or going to be hit by a fire, flood, tornado, or other natural disaster, do you have a bag you can grab on the way out the door that you could live out of for a few days? If you have a family, think of them too. Consider that maybe you already have a kit in your car as a starting point if you can grab it.
Anyway, just think about why you want a bag before you start buying stuff you found on some list on a website. We've all been there, and probably have boxes of extra junk we're not using to prove it.