1. Don't get milk, stupid
Why was everyone stocking up on milk? If you lose power, milk goes bad. You shouldn't be buying masive amounts of anything that needs to be refrigerated. Get stuff that is non-perishable: water, bread, cereal, beef jerky, chips.
2. Think ahead when buying booze
People like using storms as an excuse to drink. Makes sense. But remember that your beer will be piss-warm a few hours after you lose power (fridge should keep stuff cold for 4 hours, if you don't open it much and let cold air out). So buy some alcohol that doesn't need to be cold. Wine and liquor. And don't mix your vodka with orange juice. The juice will get warm and go bad. I suggest cranberry juice, or use pouches of Capri Sun. Anything that doesn't need constant refrigeration.
If you must have beer, you can get bags of ice, keep them in the freezer until power goes out, then put them and your beer in a big cooler. Keep the beer in a cold room away from people (people are warm).
But get beer that doesn't have to be ice cold to be drinkable. No Keystone, not even Bud Light or Miller Lite. Think Guinness, Newcastle, Sam Adams products.
3. You need tons of water
If there's flooding, town water supplies can become contaminated. That's why you need a lot of water. One gallon, per person, per day. Water to drink, water to cook (if you can), and clean yourself up.
4. Be smart with your phone
If the power goes out, your phone usage will probably go up. You'll watch movies, post on Facebook about the storm (that's not getting old at all these last few days), and pretty soon your batteries will be low. And you won't be able to recharge them. So if you don't have a charger in your car that you can use, be cautious with your phone usage. And keep your phone plugged in until the moment you lose power.
5. Get gas
Everyone was lined up at the pumps yesterday because you need gas just in case. Gas pumps don't work without electricity. And prices will go up because of the storm anyway. So not a bad idea to fill up.
6. Do laundry
If you're at the end of your wardrobe cycle, do some laundry to make sure you have enough clean underwear for a few days. That's a problem you just don't want to have.
7. Hit an ATM
Never know what you'll need cash for.
8. Batteries, flashlights, candles
Candles are fine, and don't need batteries. DO NOT use gas/kerosene lamps or anything with a fuel in it.
9. A generator will make you king of the neighborhood
Power is out, you have a generator, and booze. And the cute girls next door have nothing to do and are in the dark. Generators aren't cheap, but they have a potential to help you exploit opportunities.
10. Always keep cannibalism in mind as a last resort
Make a mental list of the people who live near you and think about which of them would be the best meal. Make sure you take care of them and do what you can to help them through the storm. Feed them, if possible. It will keep them from getting skinny, and make them trust you.
