Place drinking water in containers (milk jugs, large soda bottles) and fill up your bath tub before a storm.
Fill open plastic containers about 2/3 full of water and freeze in your ice box/freezer. Do NOT cover the plastic containers so that the frozen water can expand and not crack the container.
The blocks of ice will maintain your freezer items cold longer, should electric power go out.
If there is a "Boil Water Order" and you have run out of bottled water, bring water to a boil for one minute to purify. You may also purify tap water by adding 8 drops of unscented bleach per gallon or by using water purification tablets.
Eat perishable items first - throwaway anything in doubt or un-refrigerated.
Combine resources with family/friends/neighbors.
Top off your car's gas tank - avoid waiting in long lines with vehicle engine running.]
Use 2 for 1 coupons when buying canned and other non-perishable items. Put one in your pantry and one in your disaster kit.