On March 27, 1858, the French Navy wrote stripes into its uniform rules. The regulation for the seaman's marinière asked for 21 white stripes on the body, each twice as wide as the 20 or 21 navy ones. By the late 1940s, according to BBC Culture, the same striped jersey was being worn in the jazz clubs of Saint-Germain-des-Prés by Boris Vian and Jacques Prévert, and it has felt like the uniform of the Left Bank ever since.

That is the coffee shop outfit I keep coming back to: something with a little discipline in it, like a stripe or a crisp collar, worn with something soft. The point of a café morning is that nobody is in a hurry, so the clothes should look like you chose them slowly too. A button-down shirt does that better than anything, because the same shirt looks finished tucked into satin and relaxed with the sleeves pushed up.

In my café daydream, she is waiting at the counter in the Totême Garderob shirt in light blue organic cotton poplin, tucked into a cream satin maxi skirt, with red flats. For stripes, The Frankie Shop Peri is oversized blue georgette that drapes rather than stands, the Agolde Theo is a black striped poplin that looks good open over a tank, and the B Sides Nolan in blue seersucker hides the creases from the walk over. If you want plain white, the TWP Boyfriend is roomy enough to wear as a light jacket and the Dries Van Noten Casia has a cleaner, more tailored collar.

Hold any white shirt up to a window before you commit. If you can see your hand clearly through the poplin, plan on a camisole underneath.

Skirts are the quiet trick of café dressing, because they move when you walk in and look composed when you sit down. Picture her heading out the door with a baguette under her arm in the Dôen Marceline skirt, a tiered blue stripe in organic cotton, worn with a black cardigan buttoned once over a white shirt and black slingback flats.

Satin is the other direction. The Joseph Isaak maxi in cream silk satin and the Bernadette Emily maxi in navy satin both fall straight and catch the light, so a plain knit on top is all they need. The Ruohan Althea in brown satin jacquard has a wrap effect that adds shape at the hip. If you want something you can sit cross-legged in for two hours, The Park Sheryl in black stretch jersey is the most forgiving, and the Arch4 Hillgate in navy cashmere is the one I would pick for November mornings with tights.

Sit down in it before you decide. A bias satin skirt that looks smooth standing up can pull across the thigh on a café chair, and a size up usually fixes it.

What I would skip: a stiff, short skirt on a low café stool. The midi and maxi lengths here look calmer and save you the constant tugging.

A café morning usually involves a walk there and back, which is why I would keep the heel low. Our dream girl at the window seat, legs crossed beside a cappuccino, wears the Totême Wedge slingback pumps in black patent with a black jersey pencil skirt and a striped shirt, and the small wedge makes a pencil skirt feel easy rather than corporate.

For true flats, the Le Monde Beryl Luna in red is the pair that makes a navy or cream outfit look intentional, the Staud Milo in light blue is softer and very good with a white shirt, and the Manolo Blahnik BB flats in brown suede have a low pointed shape that goes with everything from jeans to satin. The Loeffler Randall Tove in dark brown suede has a gathered edge that reads a little more romantic.

If you prefer a strap, the Aeyde Annora slingback flats in black suede are almost as easy as a ballet flat, and the Lemaire Glove 80 in brown crinkled leather is the one for days when you want a bit of height.

Check the strap at the back with your heel raised. If it slips down while you stand on your toes, it will slip on every cobblestone too.

What I would skip: pale leather for a rainy walk. Save the white Chloé Suzie slingbacks for dry days.

The Breton stripe crossed from the navy into fashion through Gabrielle Chanel, who, according to BBC Culture, introduced a jersey smock with a sailor collar at her boutique in Deauville in the early 1900s. It is still the knit I picture on a café terrace. In our fashion dreams, she is at a sidewalk table with a croissant and a scruffy little dog, wearing the La Ligne Mini Marina, a cropped navy and white striped cotton sweater, with a navy satin maxi skirt, brown suede flats and tortoiseshell sunglasses.

A cropped stripe like that works best with a high waist, so the stripe ends where the waistband begins. The Guest in Residence Pebble Stripe in sage green cashmere is a softer take on the same idea. For cardigans, the Allude cashmere cardigan in lilac is what I would wear buttoned up as a top, the Nili Lotan March in black goes over every shirt here, and the Róhe merino cardigan in red adds color to an all-navy outfit. The Ulla Johnson Cassia has a pointelle knit in beige that looks lovely over a slip skirt.

Feel the inside of the cuff and the neck when you choose cashmere. Those are the spots that pill first, so a tight, smooth knit there is a good sign.

What I would skip: a long, heavy cardigan with a maxi skirt. It swallows the shape, so keep long skirts with cropped or waist-length knits.

The last two things you grab before leaving for coffee are usually the first two things people notice. Sunglasses do half the work of making a simple outfit look finished, especially on a terrace in October when the sun sits low.

The Celine Circle frames in black acetate are round and soft, and the Saint Laurent SL 567 in black is a thicker cat-eye that suits a sharp bob or a slicked bun. For tortoiseshell, the Bottega Veneta Sardine cat-eye is narrow and very Left Bank, while the Barton Perreira Butzi has a D-frame that flatters a rounder face.

The shoulder bags here are all suede or nubuck, which is the right texture for fall. The Staud Harlow in tan, with its curved buckle, is the one I picture on the woman waiting at the counter, the Demellier Siena in tan is slouchier, and the Neous Gemini in dark brown suede has leather trim that keeps the edges neat. The Fane Bra in dark brown nubuck is small and hangs close to the body, which is what you want when you are squeezing past tables.

Make sure a paperback and a glasses case fit inside before you fall for the shape.

What I would skip: a big structured bag for a coffee date. It ends up on the floor, and nobody wants that.

If I were putting together one coffee shop outfit this week, it would be a light blue button-down tucked into a satin maxi, a cardigan around the shoulders, red flats and a tan suede bag. Swap the shirt for a cropped Breton when the sun is out. On colder mornings, the same idea works with the navy cashmere midi, black tights, the brown suede flats and a black cardigan buttoned to the top.

The French Navy needed a whole regulation to get its stripes right. You only need one good stripe, a skirt that moves and a table by the window. If you want to keep browsing, I also put together Alt Girl and Hamptons Outfit.