I am familiar with a number of therapeutic approaches, and will recommend an approach based on the type of problem and it's causes. Many educational related issues can be dealt with through short term cognitive behavior therapy. In some cases, when it seems important to deal directly with underling emotional issues, a long term psycho-dynamic approach might be preferred if there is adequate resources available.
In many case the child can best be helped though the parents. For example, sometimes parents are burdened by issues that remain from their own childhoods or mixed feelings about what kind of a parent they would like to be or the like. Sometimes it is a matter of finding a parenting style that is both comfortable for the parents as well as effective for this specific child.
For relational issues between the parents and the child, I am familiar with dyadic therapy, seeing a different pair each week: one week the child and the mother, one week the child and the father and one week both parents without the child. This type of therapy is especially appropriate for preschool children with attachment issues.