I love the Fashion Lab at MAKE Workshop! It's a series of 7 classes -- 1 spent on the Tokyo Tie Bag, 3 spent on a pencil skirt (with an invisible zipper), and 3 spent on a dress. These projects were from patterns in her book, S.E.W. Sew Everything Workshop (a must have for beginners... I am constantly referencing my copy).
Diana Rupp is a great teacher, very clear and generous with her instruction. She's very knowledgeable and full of tips and best practices. Also, the fellow students are great and very supportive.
This class is best for those who want to get started in making clothes from commercial patterns. The time line is a little rushed for making the garments, but it's a great overview of making clothes. I definitely feel like I can navigate through commercial patterns now.
If you're looking for a more intensive course with more fashion indsutry knowledge and pattern customization, I've heard good things about Sew Fast Sew Easy, also in NYC. They spend at least double the time MAKE Workshop does on a skirt.
It all depends what you are looking for. I was very happy with the MAKE Workshop Fashion Lab and would highly recommend it for anyone looking for a crash course in making clothes from a commercial pattern!