I think that something that helped DS was that his dad travelled a lot, so I told him that it was going to be very similar but that from then on, he will be going with his dad a few nights a week, we talked about the 2 houses, two rooms and most importantly, the bunkbed. I also insisted for DS to go with him on the first night he was away so he didn't feel "left behind".
It worked beautifully, and interestingly, DS had more quality time with his dad in those first few years than he had when his dad was at home.
I remember reading somewhere that it is not that divorce/separation that damages the children, but witnessing all the arguments that lead to it. I think we managed the split very well and in very friendly terms, what caused the damage was the years of stress and arguments in court over the house.
I tried to shield DS about this, but exh was even showing him court documents and blaming me for trying to keep "his" money, and asking him to steal documents from the house for him or else. So keep the children well out of the discussions, and take good care of yourselves too because angry stressed parents find it more difficult to be good parents.