What is the general term for a cosmetic service focused on hand care, nail care, and polish techniques?

The term for a cosmetic service that specializes in hand care, nail care, and polishing techniques is "manicure." This service primarily involves the grooming and beautification of the nails and hands, which can include trimming, shaping, cuticle care, and applying nail polish. The focus on both aesthetic appeal and overall hand health is a key characteristic of manicures.

In contrast, a pedicure refers specifically to a similar service for the feet, while nail design emphasizes artistic techniques and patterns for nails rather than the overall care process. Massage therapy is an entirely different practice that involves the manipulation of muscles and soft tissues for relaxation and therapeutic purposes, and it does not specifically focus on nail care. Thus, "manicure" is the most fitting choice for the service described.