I am trying to teach myself how to fit patterns better–beyond simply shortening hems or increasing seams. I purchased a Burda pattern for a jacket with dolman sleeves (to try to copy a ready to wear item). I made a muslin in the size closest to my measurements. In trying it on, I know I need to make the shoulder area smaller (I do have narrow shoulders). The back and front sections also have side panels and the sleeve is two-pieced. Can I just shorten the top sections of each of these pattern pieces? I’m pretty confused. I would appreciate any help you can give me.