the methodology of organizational units

As a Systems Administrator there are many aspects that must be considered when planning the hierarchy of organizational units (OUs.) Organizational units are container objects within a domain that help organize objects into a tree structure. They are often used as a method of providing administrative sections when restructuring multiple domains into a single domain. A domain can be scaled to a much larger size and remain functional for the organization through the use of OUs.

What steps should go into the planning, designing, and implementation of Organizational Units? How has the use of OUs changed the structure and functionality in network administration? What would be some best practices you would implement in your OU design