Avoid The Double-Curse: Violence + Boredom
Make "even" films, not uneven films.
Avoid the double curse:
Doubly-cursed films are usually made by directors who are so established and so rich that they feel carte-blanche to set aside basic principles of marketing and dramaturgy.
Such directors make films for themselves or their investors, instead of for an external test-viewer.
Self-centered filmmakers punch up boring material with audience-restricting severity.
Or they try to add family/school appeal to excruciatingly intense material.
Only under the influence of the famous Hollywood Brain Fog could otherwise intelligent people make such mistakes.
To avoid the double-curse, always remember Tolstoy's maxim:
point every scene at a sweet 7-year old boy.
That way the scene won't be too "R-rated," nor will it be too slow.
Or if 7-year old boy test-audiences aren't racy enough for you “cool” directors, then at least point every scene at the same viewer.
That way you'll only get hit by one side of the double-curse.
Great films that fall prey to the double-curse include A Few Good Men, The Green Mile, and Amistad.
Such films tend to decline in audience appeal over time, even though they may be classics.
On the other hand, films that hit their marketing target on the head never die: Cinderella, Bonnie & Clyde, Princess Bride, Fiddler On The Roof, Sound Of Music, Raiders Of The Lost Ark, Mad Max: Fury Road, etc.
Consistent films find their audience and grow more popular every year.
Especially if they consistently appeal to friendly 7-year old boys.