It’s that time again. The Cannes Film Festival kicked off Wednesday, commencing a 12-day red carpet spectacular replete with A-list actors, models and swarms of well-dressed wannabes (with some movies thrown in the fray).

The illustrious Côte d’Azur ceremony has already seen plenty of Insta-worthy moments, and yet for every two or three fashion wins there’s a first-rate “what the F . . .?”

Indeed, despite the glamour-inspiring locale and some 70 years of chic reference points, there are those who still don’t quite get it. To help them — and everyone — better understand the dress code at this prestigious affair, we’ve gathered the good and the bad to explain how to nail (and not fail) this year’s seven most popular motifs. Voilà:

Do: feathers

Soaring victories.

Don’t: butterflies

Also: bad tans.

Do: Flaunt 3-D petals on diaphanous fabrics.

Think “A Midsummer Night’s Dream.”

Don’t: Flaunt painfully obvious petals on a prom dress.

Or you’ll end up channeling “Carrie.”

Do: a subtle touch on the décolletage

Delicate and divine.

Don’t: a full-body infestation

Over-the-top and tragic.

Do: Don an elegant column or supremely regal folds.

Two queens, one Cannes.

Don’t: Dye your hair this awful color . . .

. . . and then pair it with this awful dress.

Do: Try forward-thinking cutouts.

When you look as good as these two, no one will question why you’re there.

Don’t: Try the tired sheer trick with granny panties.

Comment dit-on “dated” en français?

Do: Keep it relatively tame, as to not completely overwhelm.

See, there’s a simplicity to the drama.

Don’t: Completely overwhelm.

This is a lot of look.

Do: Wear a beautiful dress.

It’s kind of a no-brainer.

Don’t: Let the dress (and wings and tornado hair and heavy jewelry) wear you.

Just. Say. No.