As a start, I quote from the erotic novel “The teacher in the sex trap!, Part 1” by an author who has chosen the pseudonym Caroline Milf for herself. I use the example because the author does not only describe the shape of a breast with one or two keywords but takes her time for the description.  The color and shape of the breasts themselves she describes just as clearly as those of the nipples, painting a picture that definitely sticks after reading:

Just at that moment it happened that one of the boys took off little Asena’s brassiere, because when I looked through the keyhole again, the young Turkish girl was sitting blithely, without shame, without embarrassment, with her upper body naked in front of the boys. She had really cute, incredibly pointed breasts that stood up steeply. They were almost as well tanned as the rest of her upper body, but her nipples were of a surprisingly bright red, and they were already protruding a little bit. 

Caroline Milf: Der Lehrer in der Sexfalle!, Teil 1

This takes her one step further in the question of how to best describe a bosom. Caroline Milf takes four steps in this short scene:

• She describes the shape of Asena’s bosom as “pointed.” We had already thought about the shapes a breast can take yesterday, so I won’t say much more about that at this point.
• She goes into the skin color and distinguishes it from the color of Asena’s other body.
  This will be another special topic here on the blog, especially since the skin on the bust itself is often two-colored, due to the wearing of bikinis.
• It goes into the color of the nipples.
  This will also be a detailed topic here in the blog. Because with the color the entire color scale is conceivable from the tender salmon pink up to a strong dark brown. Makes sense to take a closer look at this palette.
• It addresses the shape of the nipples.
  Caroline Milf just hints very effectively here, “her nipples were of a surprising light red, and they were already protruding a tiny bit. “
• In addition, the size of the areolas varies, not to mention the shape of the nipples themselves. Did I mention slip nipples? The fact that in some women the areolas grow when aroused? Want more examples?

A sunny afternoon at the beach. A woman took off her bathing top to sunbathe. Small, firm breasts with a gently sloping profile like small hills were revealed, pale pink skin, delicate areoles in a shade of pink, barely distinguishable from the skin. Small, almost colorless nipples like cherry blossoms straighten up in the warmth.

Another woman enjoyed the sea. Full, heavy breasts heaving with every step out of the water. Her nipples large and dark brown, wide areoles in a deep mocha shade, contrasting on bronze skin. Dark nipples like ripe currants contract in the fresh breeze.

In the shade of a café, a woman tried on a new dress. Medium-sized, round, firm breasts like two perfect hemispheres, warm caramel skin. Small areolas in a soft brown like freshly brewed coffee, medium-sized dark nipples stand out clearly, reacting immediately to the cool air.

In the evening, in an intimate setting, a woman revealed her breasts in the candlelight, long and slender like two elongated drops. Ivory-white skin, large areoles in a striking pink, almost glowing in the dark. Large, firm nipples in an intense pink, like small rubies in the flickering light, hardening at the slightest touch.

If you now feel like describing something other than 08/15 breasts in your next erotic story, you can use the breasts from the breast gallery of the website “007 Breasts” (007b.com/breast_gallery.php) as inspiration. In this gallery, you can find selfies of various women, commented by themselves. In these pictures, the range in shape and color becomes nicely clear.

The breast gallery of “Bravo” (bravo.de/dr-sommer/brust-galerie-schau-welche-unterschiede-es-gibt-172473.html) is a bit more standardized. The pictures here are supplemented by explanatory texts about the developmental phases of the breasts.