Revit has great features for using your linked files for underlaying using to trace over in both 2D or 3D. Using halftone, you can easily distinguish what is your doing and what is underlay. But how do you change your Halftone/Underlay options in Revit?
Manage > Additional Settings > Halftone/Underlay
Consider when using this, it is project wide and will affect all halftone/underlay.