On an average day, we use three outfits (two day outfits, plus pajamas). On a bad day, we use maybe five outfits.
We bought mostly clearance or lightly used clothes and I'm glad we did because these small clothes (newborn and 0-3) do not last very long; and thus the used clothes are in great condition when we bought it.
What we use a lot of:
Footed sleepers (we like the snaps for at night because I don't have to undo the swaddle sacks all the way to get a diaper changed; the zippered ones he wears in the day)
Outfits (onesie, pants, and sometimes a sweater)
Jacket- he has a little jean jacket and a little fleece jacket. Since our house is warm, he usually can wear just a sleeper, and then when we go outside I put him in a jacket and with a blanket. (Rather than him wearing a onesie under a sleeper.)
What doesn't get used a lot:
Outfits that are shirts and pants don't get as much wear because we end up having to put onesies under them or his shirt comes up, exposing his belly.
Sleep gowns- I heard good things but they don't fit well with our swaddle sacks for night time, and his little feet got too cold since he kicks them out.
Socks- most things have feet
I do not know why in the world they make tiny baby pants without snaps. I love his jeans because I don't have to take them all the way off at every diaper change.