The process of determining what type of child custody arrangement will work for your children can be complicated. There are several things that you can do that might help to facilitate a respectful and productive negotiation process for all matters related to the children.
Remember that you have to put the children's needs first. It doesn't matter what is easiest for you or hardest for your ex. When you make up your mind that you are going to focus solely on the children, you may realize that many factors simply fall into place because it is obvious that what will be best for the kids.
Unless there is some form of neglect or abuse against the children, the courts have determined that kids need a relationship with both parents. You might be tempted to point out all of your ex's flaws, but doing this can only make things more contentious than they have to be. Instead, remember that just because your marriage didn't work doesn't mean that your ex is unsuited to be a parent.
Be willing to compromise. There is a chance that you will get everything that you seek in the child custody case. But you must keep in mind that your ex is also trying to do what is best for your children. When you decide that you will work as a team in a respectful manner, things can get decided much easier.
Remember that the parenting plan you agree to is what is going to govern your children for the long-term. While it is possible to modify it, it's better to get it right the first time and avoid having to return later to court.