Custody Considerations: Step-By-Step -P1

Consideration #1: Type of Custody Arrangement
One of the first steps in determining who will get custody of a child is to understand your options regarding different types of potential custody arrangements. For example, you and the child's other parent may wish to work out an arrangement under which you both make decisions on the child's upbringing and welfare. This is called "joint legal custody" in most states. Or, you may feel that your child's other parent is currently unfit or incapable of any parental responsibility, in which case you may wish to pursue "sole custody" of your child.
Consideration #2: The Decision-Maker (Parents or the Court)
Often the answer to the question "who will get custody?" will be determined in large part by the process that is followed by the parties involved in the child custody situation.
The Parents as Decision-Maker. In most situations where parents reach an out-of-court agreement on child custody and visitation, the question of "who will get custody" is mostly up to the parents themselves, usually with input from attorneys, counselors, or mediators. An out-of-court custody and visitation agreement can come as a result of informal settlement negotiations, or after the parents participate in out-of-court alternative dispute resolution proceedings like mediation or collaborative law. In some states, divorcing parents are required to attempt resolution of custody disputes through mediation.  
If divorcing parents can come to an agreement outside of court on custody of their children, and they are able to arrange a suitable living and visitation schedule, then there is no set answer as to who will get custody. The parents may agree to a true joint custody arrangement in which their children split time living with each parent, and agree to work together on major decisions related to the children's upbringing and welfare. Or, the parents may agree that the children will live primarily with one parent, but there will be a generous visitation schedule for the other parent.
The Court as Decision-Maker. If parents in a child custody dispute do not negotiate some form of agreement before going to court, then the custody decision will be made in court, usually by a family court judge. An answer to the question of "who will get custody" is not easily predicted, but in making child custody decisions most courts follow a certain procedure, adhere to a number of common principles, and look to a standard set of considerations.