One of the most difficult things for a divorced parent is to continue to communicate with their ex about the children. Unfortunately, there isn't usually a way that you can avoid this, so coming up with a plan to reduce the stress during the communication becomes a priority. Even if you can't make every interaction joyful, you might be able to at least remove some of the negativity.
There are circumstances that might make this difficult. For example, a narcissistic ex can mean that you rarely have a decent conversation. No matter what type of situation you are dealing with, you can often find ways to make things a little easier.