Music Videos --> Commercials --> TV --> Feature Films
That's the arc of editor Sven Budelmann's career and he has some seriously excellent credits to his name including All Quiet on the Western Front, Dark, Deutschland 83 and Last Light.
His experience working in so many different arenas has given him a broad palette of techniques to draw upon when tackling different types of material.
For example, when he's cutting an action sequence today, he pulls selects the way he did when he was cutting a commercials.
My other main takeaway from Sven's answers?
Make time to try things out, like you would if you're cutting a music video.
In my experience cutting music videos pushes you to be endlessly creative, which is a good discipline for any editor to practice!