The wishes of the parent or the parents as to custody
This one is almost always a wash. Often, though, one parent wants sole custody and the other wants joint. This can be a sign that the parent seeking sole custody is being unreasonable. If there are good reasons for sole custody, as indicated herein, an award of sole custody will likely be ordered.
The wishes of the child as to the custodian
The child's wishes are always considered if the child is old enough to voice a preference. Getting your child's voice heard often takes the help of an attorney or a very mindful judge. Obviously, one is easier to find than the other.
Your child's wishes will be weighed more heavily as he/she gets older, but the judge is going to also want to know the reasons behind your child's choice. If one parent is more lax about parenting and the child wants to go there to escape the rules of actual parenting, the judge should be informed of those motivating factors so that the child's desires can be appropriately discounted.
What kind of family life will the child have in either household? If one parent has close ties and frequent contact with grandparents and other close family members, this is a positive consideration that the judge will factor in. Step-siblings and step-parents are also important.
If you don't have these relationships, you should be prepared to present a case that the child receives far more individual attention while in your care. If you are working a difficult work schedule or travel frequently, though, it may hinder the possibility to exercise joint custody. Physical abuse would also be a consideration in this category since the abuser, if there is one, is not always the other parent.
The child's adjustment to home, school and community
Judges like to keep the status quo and ease into any changes gradually unless there is an urgent need for an abrupt change. If the child's environment is turbulent with the other parent, he/she is not likely to be well adjusted to it.
That said, if there is a way to keep the child in the same school, with his/her friends it will be a great source of comfort for the child. While you may not like to admit it, children's relationships with peers have a HUGE influence on them. When they are experiencing stress at home, peers will probably help them through it. Physical abuse may also be a consideration in this category.
The mental and physical health of all individuals involved
If there are significant issues of either mental or physical health of either parent that would interfere with an award of joint custody, these issues should be brought to the judges attention. Sole custody will likely be awarded to the healthy parent and the judge may place limitations on the unhealthy parent to ensure that the child is protected.
If you are the one with the problems, be mindful that these conditions will likely be temporary until the issues are addressed. If the issues are being addressed by the appropriate professionals, this fact also needs to be presented to the judge. If you have issues in this category, an attorney's help would be highly advised. Drug usage also falls into this category.
Barriers to parenting time
The parent more likely to allow the child frequent and meaningful continuing contact with the other parent is more likely to be awarded sole custody. Preventing the other parent from forming or maintaining a relationship with the child is often not in the child's best interests. If the reasons for preventing access are reasonable, you may want to request temporary orders to have the judge order the appropriate safeguards in the other parent's parenting time.
Whether one parent, both parents or neither parent has provided primary care for the child is an important consideration. A stay-at-home parent, however, may be forced to work in the event of a divorce and both parents will likely want to have similar access. As noted above, the judges like to ease into changes gradually and the primary caretaker often remains the party with the lion's share of the parenting time.
Since custody deals with major decisions regarding health, education and religion, though, the primary caretaker is typically the parent most involved with medical caretakers and educators and may have a keener insight in these areas. If you are not the primary caretaker, start taking a very active role in your child's education and health care issues. Doing so indicates to the judge that your desire or either joint or sole custody is based on honorable intentions.
Is there an agreement regarding parenting time?
If so, what was the nature and extent of coercion or duress used by a parent in obtaining this agreement. If you haven't seen your child for quite some time or have been emotionally controlled during the marriage, this likely impacted your decision to sign any such agreement.
Compliance with child support
While not a determining factor, if one of the parents is not current in his/her child support obligation, the judge will question the motive behind the desire for a certain custody determination. This is typically not one of the most important factors but, if the judge is on the fence, this issue will likely play a great part in the final decision.
False reporting of abuse
False abuse reporting is difficult to substantiate since parties often report anonymously. This is also a huge red flag that the reporting parent is placing high barriers to the other parent's exercise of parenting time. An attorney can assist you in discovering appropriate evidence to present in support of this claim.