Which technique is NOT commonly used for nail art application?

Soaking is not commonly used for nail art application because it primarily serves a different purpose in nail care and enhancement. Soaking is typically a preparatory step for softening the nails or cuticles, ensuring that they can be easily shaped or removed. It is generally a necessary part of nail maintenance, especially before procedures like manicures or pedicures, rather than a technique used to create or apply nail art.

In contrast, hand-painting involves creating designs directly on the nail surface using brushes and polish, making it a fundamental method for achieving detailed nail art. Stamping utilizes specialized plates and tools to transfer intricate designs onto the nails, offering a quick yet artistic result. Using decals or foils allows for the application of pre-made graphics or embellishments, providing variety and creativity in nail art designs. These three techniques are specifically aimed at enhancing the visual aspect of the nails, illustrating that they are integral to the nail art process.