The essential $25 add-on for shooting cinematic footage (and why Sony ZV-E10 II samples look bad)

I noticed a lot of terrible-looking video footage in reviews for the new Sony ZV-E10 mII, and it all came down to a problem that's solved with a simple $25 add-on: the humble ND filter. Here's what it does, why you need one, and 5 simple steps to guarantee cinematic footage in any lighting conditions by using one.
(Sorry for the bit of video where I get an errant shard of a breath mint stuck on my lip. Oops.)
00:00 Intro
00:50 Telltale signs of non-cinematic footage
01:28 What is an ND filter?
03:22 Why an ND filter is needed
06:13 5 steps to guarantee cinematic footage
07:33 Sample footage