Reddit reviews The Little Black Dress: How to Make the Perfect One for You

I’ve been doing this a while. Check out a book the little black dress and build by Wendy dresses. They really expanded my skills

https://www.amazon.com/Built-Wendy-Dresses-Guide-Making/dp/0307461335/ref=mp_s_a_1_1?ie=UTF8&qid=1539774463&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=built+by+wendy&dpPl=1&dpID=51arjNZRa%2BL&ref=plSrch

https://www.amazon.com/Little-Black-Dress-Make-Perfect/dp/1861086237/ref=mp_s_a_1_3?ie=UTF8&qid=1539774530&sr=8-3&pi=AC_SX236_SY340_QL65&keywords=the+little+black+dress+book&dpPl=1&dpID=51Dtgi1b-sL&ref=plSrch

I'm sure everyone here will try to help you as much as s/he can. The best advice I can give you is to get help, as you want a professional-looking dress in a reasonable amount of time.

• Select a pattern or style you love that can be made up in different fabrics and/or easily modified.
  
  
• Make a muslin of the pattern or have a pattern made.
  
  
• Get it fitted.
  
  
• Make up the dress.
  
  
• Transfer the final pattern to a firm medium like oak tag so you can quickly trace the pattern for future dresses.
  
  
• Make notes of your experiences with fabric, thread, interfacing, thread tension, finishes, etc., so you will learn for the next dress.
  
  EDITED TO ADD:
  
  Here are some books that might provide some inspiration:
  
  http://www.amazon.com/The-Little-Black-Dress-Perfect/dp/1861086237
  
  http://www.amazon.com/The-Little-Black-Dress-Perfect/dp/1861086237
  
  For business, I think a sheath dress would be a good pattern to develop.

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.