So here is my latest discovery: it's a 15-module course by first-class professional Susan Khalje and though it's called The Couture Dress, to me the value was learning the proper way to make a muslin (aka mock-up etc.). It turns out I had been doing it wrong all those years. Not 100% wrong, but with the professional secrets I learned in this course, I know my sewing will improve.
The course is included in my monthly Craftsy subscription, or I could buy it for $30, then it would be added to my Craftsy Library where it would remain forever. I already have over 30 courses there, which I had purchased before the platform turned to the subscription model.
Craftsy changed hands recently, and now both options are available, which is just perfect.
Trust me, the muslin I'm making this week will follow all the rules I learned in this course. I'll be back here to show it to you soon. Stay tuned!