Keeping custody of your child(ren) after a divorce or separation is always a priority. Likewise, losing custody of your children because you don't do the right things with the other parent or the children is preventable. Here are some suggestions, they don't all work because every set of parents are different but there are some basics that apply to almost everyone.
1. Maintain the children's relationship with the other parent. (Of course there are exceptions where there is abuse, drug addiction, alcohol dependency and unsafe relationships between child and parent). However, unless you have a real good reason and can substantiate it, the courts view this as one of the most important factors in custody decisions.
2. Communicate with the other parent in a civil manner. Keep the other parent informed of all major decisions and consider discussion of minor decisions. If you are required to consult in advance on significant decisions, then do so. If you have sole custody, that does not mean the other parent has no right to know what is going on (but there are some situations where protection will require no communication).
3. Encourage the children to visit the other parent.
4. Consider make-ups if there are reasons why visits are missed.
5. Do not disparage or ridicule the other parent to the children.
6. Do not use the children to communicate your wishes to the other parent.
7. Do not discuss child support with the children.
8. Let the other parent know who the doctors are, the results of visits, how the child is doing in school, teacher conferences, awards and ceremonies involving the children. While it is easy to say just look it up, you get major points if you facilitate the sharing of information.
9. Take the high road when the other parent goes low.
10. Don't ask the children to take sides or to choose.
11. Do not grill the children when they return about the other parent, their home, their relationships, etc.
12. Let the children express their feelings without being made to feel guilty.
Preserving the children's relationship with the other parent (unless there are reasons otherwise) is the best way to maintain custody of your children. Of course, there is work to be done with your children and there are dos and don'ts that may not even involve the other parent. However, if you do the above it is far less likely that a custody modification will be successful.