The top is knitted bottom up starting in the round and then divided in two cups that are knitted flat.
You can knit with fine or DK yarn in 1 strand (orange top in the image), or you can combine super fine or fine yarn with silk mohair for a softer texture (blue and lilac tops in the image).
The yarn amount for different sizes (this amount is of fine yarn type, and is an estimate and may vary based on the type of yarn you use and your personal gauge/ tension):
in meters: 70(170m-180m-190m)/ 75(180m-190m-200m)/ 80(220m-230m-240m)/ 85(230m-240m-250m)
in grams: 70(50g-54g-58g)/ 75(54g-58g-62g)/ 80(70g-74g-78g)/ 85(74g-78g-82g)