Thought this might be an interesting topic to discuss. I've posted this on another thread, but here is what my mum 'had' to do in the mid 70s.
Baby must not have anything to drink for 12 hours (although I was 'lucky' and allowed half an ounce of water out of a bottle).
After 12 hours, offer each breast for 1 minute each. Then offer 3-4oz formula.
Repeat at 4 hourly intervals.
Day 2 - offer each breast for 2 minutes each. Then offer 3-4oz formula. At 4 hourly intervals
Day 3 - offer each breast for 3 minutes each side, then offer formula, 4 hourly intervals.
Etc etc. They all stayed in for 12 days. I have all the feeding charts etc. And they were RIGID in their rules.
Things I was told - baby only needs to feed every 7-8 hours, especially a 'big' baby as they have lots of reserves.
Missing a b/feed and replacing with a formula feed increases your milk supply as you have time to make more.