Under-developed, tuberous breast - how can I achieve a C cup? (photo)

It's difficult to give recommendations with photos of only one breast. For asymmetry and tuberous breasts you can consider downsizing the larger breast to better match the smaller one and using implants to help with shape. A breast lift is often indicated to help with symmetry of the nipples.

Dear lisieleigh,
tuberous breasts are not simply small or underdeveloped breasts. The appearance of the breast can range from mild to severe, and typical traits include: enlarged, puffy areola, rather wide spacing between the breasts, very little breast tissue, sagging, higher than normal inferior breast fold, and narrow base at the chest wall.The type of surgery best for you will depend on the severity of your condition.My preferred technique for tuberous breast correction involves a multistep procedure where the breast tissue is released in a radial pattern to prevent herniation into the areola and placement of a custom implant size is in the breast to allow appropriate expansion of the breast in the restricted dimensions. This can often be done in a single procedure but sometimes may require two surgeries.That said, it is best that you visit a board-certified plastic surgeon for an in person examination. Only after a thorough examination you will get more information and recommendations.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

The one photo you posted of one breast is not tuberous, but is small. An augmentation with implant placed behind the muscle would do well for this breast.