For example, if someone admires a painting and says "C'est une belle touche!" they are praising the technique, color palette, composition, or the overall aesthetic of the artwork. In the context of fashion, "belle touche" could be used to describe a well-coordinated outfit or an accessory that adds a stylish finishing touch.
Overall, "belle touche" is a term of admiration for skilled craftsmanship, artistry, or the attention to detail that resulted in a pleasing or impressive outcome.