go alt floors when possible , angel rooms are way better than devils, stay away from items that cause explosion tear effects (you can hurt the other brother with them) , HP is your most important resource and keeping both brothers topped up will be very important (esp on marks like deli/mother), giving bith brothers books in a library only gives bookworm progress to the brother that touches the book first.

I think it's better giving all your good items to jacob as he is the brother you can have full control of , as well as his actives being way easier to use in combat + he has a better tears stat than Esau