Someone wanted to learn this too, so Grasp built them a personal learning path.
You can keep exploring this one or create a path like this one shaped around you.
Recommended resources
Module 2
Designing the Custom Elements
Module 3
Drafting the Custom Patterns
Module 4
Technique Mastery & Prototyping
Module 5
Final Bodice Construction
Module 6
Final Skirt Construction with Godets
Module 7
Main Assembly & Closures
Module 8