The suggestion to start with inexpensive fabric and make a trial is good. I have used this for some of my garment sewing. Princess lines work good for us plus-sized women, drawing the eye up and down instead of across. You have a lot of good suggestions here, but the best is to find a mentor. If I were close, I would volunteer. It sometimes helps to see what needs to be done, and get on-the-spot help when you are working on something new.
Your question reminds me that I need to find a pattern for a blouse and get busy! :roll: :lol: