I give newly captured slaves a day off their first day in-house, two days sometimes, and when I've start harvesting the flowers over at Mai Lynn's place I'll give newly captured slaves one as a gift. Immediately after capture take them to the diner and feed them but don't talk to them, and give then a $5 allowance if you can afford it. The next morning (1st day) give flowers and the day off. There will still be some work to do, but that makes a good start -- and if they have traits compatible with your House then you'll be almost there already.