The style lessons continue from model Kaia Gerber's casual “fit.” First, she taught passersby on the sidewalks of Soho how to dress (chicly) in black and navy.

Kaia Gerber wore a very '90s black slip skirt for a night out with boyfriend/actor Austin Butler and best friend Camila Morrone on Tuesday, July 16. I didn't need to add many items to create a Caroline Bessette-Kennedy look. Timeless black ballet flats, a black Celine shoulder bag, and a coordinating black tank top (with a little belly showing) were all she needed.

Simple yet effective: that's the motto of Kaia Gerber's summer look. While head-to-toe black might read “aloof fashion girl” to some and “off-duty gothic” to others, her blend of tiny cropped tanks, flowing slip skirts, and classic flats truly falls into the vintage chic” category.

Her late-night outfits continued the styling pattern. This summer, Kaia Gerber has been leaning heavily on moody neutrals and leather shoes; on July 11, Gerber attended the opening night of Cole Escola's satirical Broadway play “Oh, Mary,” again in a 90s slip skirt, She chose a grayish black with contrasting diagonal stripes. She styled it with a cropped T-shirt and shiny leather boots.

Kaia Gerber's all-black summer look goes beyond the 90s slip skirt. She has showcased a number of summer LBDs with short puff sleeves and romantic tie detailing.

This is not to say that the bottoms actress is allergic to color. She took a day away from her all-black summer attire last week by wearing the summer trend of white skirts and electric yellow T-shirts. For the press circuit for Apple's “Palm Royale” TV show, she wore an electric blue mini-dress and a 60s metallic swing.

The real takeaway from Kaia Gerber's all-black outfit is that simplicity is never stupid. Her latest look is as close to “effortless” as you can get.