I think that it would be worthwhile to offer a tutorial that deals with design approach and the interaction between sketches and shapes.
It seems to me that a sketch should be minimal to define an outline and that it should be Shaped ASAP so that you can use the many and powerful 3D tools. The tutorial should show the automatically created sketches done by using the 3D tools.
For example, if you do a lot of 3D work with Offsets and Insets you may be surprised to see all the new automatically created sketches. If you delete the 3D shape, the Sketch lives on and this can become confusing. So good Groups housekeeping is needed.
And some guidance on modifying sketches or the need for new sketches; that is when you have to go back to 2D to solve some problem you can’t seem to handle in 3D. And some guidance on if and when to delete sketches…
We need an expert to explain best practices.