A bugout bag for each family member, containing (among many other things already mentioned):
Common items (such as our pool of food...all MREs) spread evenly. We have sufficient food for a family of 4 for 30 days.
A firearm assigned to each person plus ammo, and their choice of a firearm plus ammo.
Each one has a green smoke grenade and a maritime-type waterproof flare gun, spotting glasses and a whistle.
Two catydid reverse-osmosis water purfification kits plus battery-powered ultraviolet sterizier (add solar powered battery charger, 12-volt).
All my family's important documents sealed in multiple ziplocs. DLs and other IDs get tossed in when the time comes.
A separate SHTF case that can be carried by 2 adults and tossed into the back of the Hummer with more gear: tents, camoflauged material (12'x12') desert pattern.
Entrenching tool.
Spool of CAT2 station wire (2-wire phone cord).
An assortment of otherwise inert chemicals that I know how to use properly.
20' of primacord, acquired and possessed legally.
50 silver Mexican Peso coins from the 1800s, for barter.
Two complete ladies' makeup kits (for my wife and kids to use as barter goods).
My reloading kit plus 10,000 primers each of SP, SR, and LP, and gunpowder. Includes my bullet moulds and propane kiln.
The Hummer always gets tanked up at 1/4 tank, so it is always full, and has 2 5-gallon jerry cans on the spare tire carrier, and two more cans can be lashed to the roof rack.
75-lb pull compound bow and assortment of broadhead and narrow point quills.
Bible double-wrapped in plastic bags.
At a location some distance from where I live I have buried some other interesting items, which include several firearms not traceable to me and ammunition for them. An old Hallicrafters shortwave radio, 2 12-volt car batteries and a WW2-style hand-cranked generator and another solar 12-volt charging panel. Extra clothes for winter (you can always cut them up in the summer, and if it'll be your 2nd post-apocalypse winter and you are still wandering, you need to change your game). Packages of seeds for fruit trees (Cherries, applies, dried tomato seeds, and such). 2 ER surgical kits (my wife is a nurse). A sealed shoebox full of dessicant packs and a bunch of ziplocs in many sizes, for whatever we may come across. A polaroid 660 camera and 15 packs of film for it (I know, the film is expired so the colors will be off, but after time the colors will fade anyway). A spare Dell Mini netbook (320GB SSD drive) and extra battery pack for it, with car charger. It has the Microsoft GPS receiver built into it. A handheld police scanner (rechargeable penlights) and an old portable Airband VHF and commercial AM/FM receiver (rechargeable D cells). Two cases of MREs sufficient for my family of 4 for 60 days and four cases of 24-pack bottled water. About once a year I go out there with a friend (who acts as lookout) and dig it up and replace things like the batteries. The Dell netbook I just added last year.
As long as my house doesn't burn down, there are other items I have secured around the outside of the house that I can come back for if needed, like ladders, shovels, empty gas cans (valuable when scavenging) and 2 sheets of 4x8 7-layer bulletproof glass. Don't know why I ever got it, but I got it and who knows, I may need it?
Depending on what happens, a quick bugout GTHOD (get the hell outta dodge) escape may be all that is needed plus lay low for a while. If the situation deteriorates or does not improve, then the buried cache gets dug up.