A good optional thing to have in your 72 Hour Kits, especially if you have small children, are matching family t-shirts.
In case you were separated from your family, it would be much easier to say: "Have you seen a small girl in a pea-green t-shirt with the number 4 on the back?" rather than saying "Have you seen a little girl, this tall, with ______color hair?"
All you need are some matching t-shirts and transfer paper. I found these shirts on clearance at JoAnn's for under $2 each.
Choose something to go on your t-shirts. I chose a family nickname for the front and numbers for the back (Mountain Man gets to be #1). Another family I know has a Dr. Seuss character plus "Thing #1" "Thing #2" and so on. Another fun idea is to buy fabric markers and have each child color on his or her own shirt (a fun FHE activity). It would provide a great opportunity to talk about stranger danger, or family emergency plans while coloring on clothes.
One caution: don't include your child's name on their shirt! I would go so far as to say, don't include your last name on your shirts. I hate to seem paranoid (actually I don't really care if I seem paranoid or not), but you don't want your kid to go off with anyone who calls out their name. Child predators are everywhere, even present during emergencies.
Just thought you'd be curious about my blog to-do list, someday I will do another Q&A.
After deciding on a text or image for your shirts, print out a practice sheet on regular printer paper. You don't want to waste valuable transfer sheets. Also, read the instructions on your packet of transfer paper. Some will have you reflect your image before you print it out. Mine didn't but I reflected it anyway---so the '4' will be backwards. If you see a child with a backwards '4' on a pea green t-shirt, please return her to me immediately.
Let the transfer sheets dry for at least 30 minutes after printing. Then trim them down to size. Some transfer paper will go on clear around the edges (just imprinting the image) and some will copy the white as well, so read the instructions.
All transfer paper that I've ever used has you use a hard surface (like a wood cutting board) for ironing, instead of an ironing board.
Cover the cutting board with a pillowcase and iron out the wrinkles on the pillowcase and the t-shirt before starting.
The iron should be on a 'no steam' setting. Position your backwards '4' where you want it to go, and apply as directed by your instructions.
Just for your information, this isn't the type of transfer paper I used this time, but it's the kind I prefer to use.
Put each person's t-shirt in their 72 hour kit so if an emergency situation comes, each person can don their own shirt right away to be prepared in case you get separated.
It's okay to hope that you never have to use them, I am.
P.S. I purchased adult 'small' shirts for my children even though they are small. I can tie up the shirt in a side knot 80's style until they are older and I don't have to worry about rotating them...ever.