The general idea is -- the more stuff you can have prepared NOW, the more stuff you'll be able to do when everyone else is running around like a chicken with its head cut off.
For starters, don't sit there staring at the tube (or monitor) -- get out FAST and buy a bunch of supplies, whatever you can. Gasoline, food, water, medicine, vitamins, cooking fuel, etc.
You want your prep run on "the morning of" to be a BONUS run, to get a few extras or perishable goods -- not a shopping trip that your survival will depend on!