I was digging around some old fan magazines, as I do, and I found this extremely enjoyable double interview with Cecil B. DeMille and Jeanie Macpherson in a 1920 issue of Screenland. What could filmmakers do to keep their audiences?
Fan magazines are notoriously unreliable sources and some interviews are pure bunk. That being said, I can’t picture DeMille letting someone put words in his mouth and what is said here does match the style of DeMille/Macpherson collaborations.

Oh, and I should also say that many people get hung up on personal matters between DeMille and Macpherson but they forget that she was a director in her own right before joining DeMille’s creative team and, in my opinion, her writing was what made DeMille DeMille. They shared a love for bonkers sleaze and her unconventional religious views tempered his own instinct to preach. Also, he couldn’t spell and she couldn’t punctuate. It was a perfect creative match.

Dare I say he was her muse? Dare I? I dare! Mwahahahaha!
Alfred D. Wilke interviewed the duo to ask an important question:

Intertitles: The Right Way and the Wrong Way
“If I were asked to name the largest and most important reason for this trouble.” said Mr. De Mille. “I would unhesitatingly say, ‘Too many subtitles.” There are other reasons, some of them important and more or less obvious. But too many subtitles have ruined more continuities than any other one cause. “
“The effect of a subtitle is always to jar the spectator just a little out of perfect harmony with the pantomime story,” continued Mr. De Mille. “That doesn’t mean that subtitles should be excluded from the finished photodrama. They — subtitles — have a very definite place. But a super-abundance of them will inevitably result in the loss of the spectator’s attention. Subtly, by stopping the smooth flow of the photoplay, the printed words break the thread of attention which should bind the audience and the picture together.”
“And subtitles must be in ‘key’.” added Miss Macpherson, “even where the number is kept to the required minimum, it is very easy to lose the spectator’s interest by flashing subtitles which are not in perfect harmony with the theme of the story. All too often the title writer makes the mistake of attempting to inject a humorous twist to a
serious scene, with the result that the situation falls flat and the audience is ‘lost’. “
Note: This is a pet peeve of mine! Modern people making silent films think that the silents were all about the title cards and stuff their pictures to the gills; each time a character opens their mouth, a title card appears. That was not the case at all!

Stuff: How Much is Too Much?
“There’s another effective way of losing one’s audience,” resumed Mr. De Mille, “and that’s by giving the spectator too much to look at. I don’t mean too much in the way of a story or of acting. I’m referring to the material side of production. Too much furniture: over-elaboration of backgrounds: too much scenery; too much design in wallpaper and so through a dozen other angles of staging.
“The effect on the spectator is decidedly confusing. Facial expressions are completely lost in the super-abundance of detail. The spectator is so busy trying to see everything on the screen that the vital thing — the fine shadings of the acting — are lost.”
“Backgrounds should be for effect alone,” continued Mr. De Mille. “Whenever a background assumes more importance than the acting, it has a dangerous effect on the attention of the spectator.”
“Costuming likewise has a powerful effect on the spectator. Just as backgrounds must be in harmony with the situation, so clothes must play their part. This is particularly true in the case of the women of the screen. They must wear ‘mood dresses’: the wrong kind of dressing ruins the mood of the scene; the right kind of dressing can do much toward making the scene.”
Note: This may seem a bit odd considering DeMille’s reputation for “too much is never enough” but at this point in his career, he specialized in smaller, punchier pictures. Marital comedies, melodramas, that sort of thing. If you only know DeMille from his talkies, prepare to be pleasantly surprised. Also, “mood dresses” aplenty.

Music
“Don’t forget the theater music” — this from Miss Macpherson. “Of course that is something over which we have very little control. But it is really very vital. I don’t know why theater managers persist in giving their patrons The Rosary and jazz in about equal quantities without regard to the theme of the picture.”
Note: Relatively few pictures had bespoke scores at this point in history. Some were released with cue sheets and many were simply left up to the house musicians. Poor playing, music selections and instrument quality were common complaints.
If you want to know more about Macpherson and DeMille’s collaboration, I wrote about it in my reviews of Joan the Woman, The Captive and The Unconquored, the first movie Demille completed after Macpherson’s death.
that headdress!
Jeanie was quite a gal in the screenwriting department. It’s a pity Linda Griffth knocked her acting abilities in her book, but perhaps that’s why Jeanie gave up posing altogether.
She was quite excellent in Carmen. Macpherson probably just performed better when working with a director who didn’t think smooching birds was the height of romance. 😉
Yeah, I totally side-eyed DeMille’s comment about, ‘Don’t go nuts with those backgrounds now,’ because…sir. Sir. I want you to take a long hard look in the mirror and say it again. But MacPherson was totally on point about a bad soundtrack absolutely ruining a movie, I say having viewed a REALLY bad print of Phantom of the Opera where Bach’s Tocata and Fugue was literally the only piece of music…I think it was played on a synthesizer.
In all fairness, DeMille had luxurious bathrooms and that’s about it at this point. Even Joan the Woman, his biggest picture by far at this point, kept things relatively simple. Or as simple as a film with medieval castles can make it.