Your number one concern is to make sure each child has a parenting plan that nurtures growth into a happy, healthy, and productive adult. Consider individual temperament and flexibility, and how well each of your children deals with change. Divorce subjects children to trauma, no matter how well managed and peaceful it may be. Your kids will be afraid, and may feel that they are losing one parent.
Different schedules suit children of varying ages best. For example, shorter stays may be more appropriate for young children, while teenagers might prefer longer visits. Include these considerations in discussions with your attorney and in negotiations with your spouse. Advance planning that adjusts for personality traits in children can diminish or erase many difficulties down the road, after the divorce is finalized.
The idea is to create a plan that eliminates as many reasons as possible to have to go back to Court and ask for modifications. Court visits always mean more cost and conflict, and potentially adverse outcomes.