It depends on how long we are going out for but if we are out for longer than an hour Ill take

Nappiesx4
Wipes
wet bag
spare jumpsuit,singlet and socks
face washer for spew
toy of some sort


And now DD is a bit older

Spare bib
Sippy cup
food
spoon
baby sunscreen
hat

And then my wallet, phone etc. I think thats everything! I forget at least one thing without fail everytime we go out though

HTH