Which of the following techniques is essential for barbers to master?

Mastering the technique of shaving with a straight razor is essential for barbers because it is a fundamental skill in traditional barbering. The straight razor provides a close and precise shave, which is often a service clients expect from a professional barber. This technique requires a deep understanding of blade angle, pressure, and skin types to ensure safety and achieve the best results without causing nicks or cuts.

Moreover, the straight razor shave also involves the application of various techniques such as lathering, skin stretching, and aftercare, which are critical for client satisfaction. This skill is not just about the act of shaving but encompasses a broader knowledge of facial anatomy, hair growth patterns, and the importance of prep work before the shave, such as applying warm towels or pre-shave oils to soften the hair and skin.

While the other techniques listed may be beneficial, they do not hold the same fundamental importance in the context of traditional barbering practices. For instance, using electric saws is not typically a skill required of barbers, and while performing hair braiding and understanding skin care can complement a barber's service offerings, they are not as central to the traditional barbering skill set as straight razor shaving.