Use integrated tools to trace reference geometry or sketch subdivision faces directly in a view.
Download sample files from Alias Sample Files to follow along with the tutorials.
This workflow demonstrates how you can use the Retopo toolset to build subdiv topology on meshes. You can follow the prompts in the promptline, and refer to the hotkey help card for tips.
This workflow shows how you can use the Retopo toolset to build subdiv topology on NURBS surfaces and in a flat View Plane.
For more information, see Retopo.