As I have narrow and square shoulders, I often need to adjust for that. I have both woven and knit patterns in which the sleeve/shoulder fit perfectly. I traced the armscye and shoulder areas of the F and B, and the top of the sleeve from those patterns onto a sturdy pattern material. I simply lay/pin them over the relevant areas of a new pattern (making sure of the correct shoulder width and using the appropriate knit or woven one) and cut. Works every time, even with weight fluctuations. It saves all the slashing and shifting and taping on new patterns. Patterns with intricate design elements in the upper sleeves are another issue, of course.