If you've lowered the shoulder seam on a jacket or blouse, it will also be necessary to make an adjustment on the sleeve cap.  You will have an extra 1" of sleeve cap for every 1/2" adjustment in the shoulder seam.  The easiest place to adjust the sleeve is at the underarm seam.  Begin setting in your sleeve at the shoulder seam mark, then fit it down the front and back (bypassing the original markings) and trim off the excess at the underarm seam (the same each side as at the shoulder).  Taper the trimming to zero by halfway to the wrist.