Associations for Seamstresses, Stitchers, and Tailors
The Association of Sewing and Design Professionals is a certified program for Seamstress. It offers the Master Sewing and Design Professional certification. This program evaluates your competence in seven major categories. The sewing program covers advanced sewing techniques and concepts. The program includes texture, proportion, fit, and professional practices.
There are many more associations to explore to advance your career.