Enajybbil, measuring my shoulders has only been a recent discovery for me. I think it works by the fact that if the shoulder point is sitting at the felx point of your shoulder then the shoulder and sleeves of the garment should be designed to give the maximum range of movement. I’m not sure I’m explaining well 🙁
I think weather your my bust measurement works or not is very dependent on your personal shape. Recently I discovered that even when using my high bust measurement, which is significantly smaller than my bust, I was still finding the shoulders were too wide. Although I didn’t realise that was the problem at the time.
I found this post on fitting shoulders, http://sewingnhumming.blogspot.com.au/2011/05/time-for-my-pattern-fitting-secrets.html , and got some help from my husband and discovered that my shoulders are very narrow, like 12.5cm (4.92″) and 13cm (5.1″l. Once I was using the much smaller shoulder width I got a very well fitted pattern. I was very shocked when the much lower sleeve cap was very comfortable and allowed more ease of movement without the rest of the shirt moving!
I hope this has helped somewhat.
