For me, I do once a week so
- Day clothings & PJs 7 pieces each + 2-3 spares incase or leak or puke.
Longsleeve onesies 1-2 pieces, sg hot, mostly short sleeves.
Swaddles 1 per day.
Bibs - lost count but good to have more especially if you intend to change every 2-3 feeds (or every feed if they burp out milk).