What is Reddit's opinion of The Little Black Dress: How to Make the Perfect One for You?

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Look up tutorials for a Small Bust Adjustment (SBA) and do some test runs with cheap fabric like goodwill bedsheets, just for practice. Once you've developed your skills a bit I recommend you look into making a sloper for yourself, but that's easiest when you've got a friend to help, so maybe reach out to local queer communities and maker spaces in your area to find your people.

This book is an excellent tutorial on how to make a sloper, and how to use it to pattern for yourself going forward. https://www.amazon.com/Little-Black-Dress-Make-Perfect/dp/1861086237

If you want to have one for personal use, I'd recommend against an adjustable. The best-quality personal dress form can be had by getting one very close to your measurements (but not over as you can't make it smaller), then create a toilé or muslin of yourself, fit it over the dress form, and stuff it to fullness. This will also allow easy pinning of fabric to the dress form.
There is an excellent walkthrough on how to do this in Little Black Dress by Simon Henry.