What are the most efficient workflows to create all quad junctions? In a video tutorial on All Quad Junctions some different  types of junctions are explained. When trying to create them I struggle with extra edges and merging points, ripping points. That takes too much time 

Is there a efficient reproduceable way to create these types of junctions?
The easiest way that comes to mind currently is to remove  the critical faces, add some loop cuts, then create faces.  

So for the second one, you would remove the critical face,
make a double loop cut with Ctrl R
then 2 then extrude the small edge in the middle,
and finally select the edge pairs to Fill them with F.

The same applies to the third and fourth with some changes. For
the first one: Remove the upper two critical faces, add the loop
cuts, fill the proper edge pairs, move the center vertex down.