What action helps to achieve the desired nail shape at the beginning of a manicure?

Soaking the nails is essential at the beginning of a manicure because it serves multiple purposes that pave the way for achieving the desired nail shape. When nails are soaked, they become softer and more pliable, making it easier to manipulate their shape and condition. This preparation step allows for a more effective filing process, as the nails are less likely to break or split when being shaped.

Additionally, soaking can help to clean the nails and soften any debris around the cuticles, creating a clear canvas for further shaping and detailing. This is crucial because a well-prepped nail will not only shape better but also look more polished and healthy afterward. While the other options, such as applying nail hardener, using a buffer, or trimming the cuticles, contribute to overall nail care and appearance, soaking is specifically foundational in achieving that desired nail shape right at the outset of a manicure.