This is an easy one! Get white, black garbage bags or colapsable bins to store in each room (preffereably in the closet or under the couch or bed)
Don't let an evacuation order of any kind leave you frantically packing and missing the most important items behind. Having designated bags or bins to quickly throw stuff in is a helpful start and to add to it, just make a list in each room of items you can't leave behind and staple it to the bags or tape it to the side of the box and if the time ever arrises to have to pack it up you can just quickly grab the items down the list and run.
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