Sewing a drop shoulder sleeve is like sewing a set-in sleeve with little alterations at the shoulder seam area. All you need to do is extend your seam below the shoulder bone. It would be best to sew the vertical seam for the armhole between the shoulder point and the top of the arm. If you want to sew a basic drop shoulder sleeve top, read below for the steps you can follow. Cut two fabric pieces 27 inches in length or depending on the length of top you want. Fold one by the middle and mark one for the back bodice while the other one is for the front bodice. Cut each of the front and back bodices from a drop shoulder pattern you created. Fold the bottom edge once at ¼ inch to the inside, then sew the edge. You can opt to fold another ¼ inch again along the edge then sew to have a smoother and cleaner finish. Join the two fabrics with the right sides together at the shoulder seams. Cut out the sleeve fabric pieces. Finish the other side of the sleeve fabric with a rolled hem. Topstitch the edge keeping the seam allowance of the edge to the inside. Sew the side seams of the bodices. With the wrong side of the fabrics out, sew the side seams from the sleeve edge to the hem. Do this for both sides.