I have a back-up diaper bag. "What is this?" You may ask! It's a diaper bag that stays in my car (most times) and contains spares that will come in handy in an emergency. As an aside, it also allows me to take impromptu trips with the girls without packing my main diaper bag as I know whatever I may need are in the bag.
What's in the bag?
Similac ready to feed formula 8oz bottles. 4 bottles.That's enough for 2 feedings meaning I can be away from home for 6 hours and the babies still get fed.
4 sets of bottle nipples, rings and covers to go with #1 above. I buy the $1 feeding bottles from Walmart, wash and sterilise their parts and keep in a Ziploc in the bag
Pack of store-brand diapers
Resealable pouch of wipes
Diaper disposal bags
2 weather-appropriate one piece outfit usually either a sleeper or a dress. One for each child
First aid kit
Baby Mum Mum snacks
I love the little bit of spontaneity that my back-up diaper bag gives me.