I've lived in Houston for 3 years, and after the flood the year I moved here I started a small survival kit for me, my girlfriend, and our dog. Here are my tips based on what has/hasn't worked. Be aware I haven't had to actually use the supplies, but have had to move them around a bit and have seen what disappears from stores quickly.
First, don't get a giant 25L water jug you have to fill, even though it looks cool. Filling your own water bottle is a recipe for algae and stuff in it if you keep it long term, and it'll be a bitch to move if you have to evacuate (and you will want to take water if you evacuate). Every L of water weighs 1kg (2.2 lbs for us Americans). That doesn't seem like a whole lot if it's on a weightlifting bar, but in a jug of water it's certainly not convenient. I buy the 6 pack of 1 gallon (3.8L) bottles at Costco for something like $4. You can keep them in the 6 pack for quicker movement but heavier weight, or break them up if you need to. They're also shelf stable so you don't have to worry about algae or anything. I also have at least one large package of single serve bottles for convenience. 1 gallon per person per day is the rule of thumb, I have enough for about a week (a bit less if we give our roommates some) at that rate. Also, don't get the milk jug looking bottles, they break over time. I've had good luck with this style:
https://goo.gl/images/wZvhwhGranola bars and easy to eat things are good, but I also have some ramen and a DIY alcohol camping stove in case our home gas goes out and we want a hot meal. Freeze dried veggies are available at some supermarkets, and pair well with packaged ramen to add some substance. In reality, you probably won't need much food as whatever you already have in your fridge/pantry should hold you over for at least a week. If you want to be extra safe get a few MREs or camping meals, they last basically forever and some taste pretty good. We have enough random canned food and stuff in the deep freezer that I don't bother.
For first aid, Benadryl is a must to help with possible allergies. Some of each type of painkiller like aspirin, acetaminophen, and ibuprofen is good in case you or someone you may be stuck with needs a specific one. Triple antibiotic is also good. I also like having burn gel (usually has near prescription amounts of pain reliever in it). Anti diarrheal meds and some fiber are both helpful as well, the fiber especially if you're eating a bunch of beef jerky and MREs for your diet. Be aware of expiration dates on the medicines. Don't buy a huge first aid kit that you don't know how to use with sutures and all sorts of crazy stuff. Obviously if you or a loved one have any prescription requirements, try and keep about a month's supply on hand at any given time.
An external phone battery is a good investment as well, you don't want to be like some friends of mine and have to go start up your car and burn gas to charge a couple cell phones. A radio isn't a bad idea either (although I don't actually have one). Lots of batteries and a few good flashlights are a must, although a cell phone is a decent backup. I have a camping headlamp that uses AA batteries and have probably 10 at any given time. A generator is expensive, but may be worth it depending on where you are. I hear good things about Hondas.
Another tip is keep your gas topped up in your car. If you're lazy about it like me, just go get gas any time there's a remote possibility of a disaster coming. Hurricane that is heading in your general direction? Time to fill up. Don't rely on gas stations or grocery stores being useful before/during/after the disaster.
If you're doomsday prepping for a multi month ordeal, obviously this advice doesn't apply all that much. For most "regular" disasters you'll be just fine with some extra water and a bit of food. If you live out in the middle of nowhere, prepare for a longer stay. Also knowing common evacuation routes/areas is a pretty big deal. Don't be afraid to leave early.
edit: Just started reading the sweethome article. Be aware that shelf life for bottled water is for taste/odor, not safety. It will keep indefinitely. I'd trust commercially bottled water far more than an opaque jug I filled myself. Buying it at a big box store is very cost efficient. Their 7 gallon container costs $15 on Amazon, I bought 6 gallons at Costco for <$5 (I think it was around $3 actually). Their 55 gallon drum costs over $2/gallon, again very expensive and a pain IMO, although you may get more prepper cred for it.