Use NURBS trimming to add details without increasing subdivision complexity.
Download sample files from Alias Sample Files to follow along with the tutorials.
Use the Trim and Untrim tools to add detail to the model with projected curves-on-surface and intersecting surfaces.
Use the Trim and Untrim tools to divide or split surfaces while maintaining the control cage complexity. The Object Lister displays the effects of Trim Divide and which subdivisions have construction history.