01
Length is the constraint nobody applies
YouTube truncates titles in most surfaces, and on a phone that happens sooner than people expect. A title whose payload is in the last four words is a title nobody read, however good the phrasing is.
So every title here comes back under sixty characters with the specific part at the front. That single rule improves click-through more than most of the phrasing advice that gets written about titles, and it costs nothing to apply.