First I cut off the sleeves inside the body area (removing a couple of deodorant marks) and zig-zagged quickly round them to prevent too much fraying. Then I lay out the shirt and measured the shoulder seam from collar to cut dividing up into equal sections so that I could fold, pin and iron three tucks to bring the shoulder in to just cover my bra straps:
First measured and marked out divisions with the pins
then folded one pin to the next to form the tuck
I continued these folds down the back, getting them to narrow to nothing and over the shoulder down the front about 12cm. Notice how the fold form a sort of V shape down the back.
Now at this stage it would be wise to do some basting, but personally I'm never very wise so I then set off with the sewing machine top stitching along the formed tucks. I did not start and stop right at the very ends of the folds, but varied the position of where I started/ stopped on each fold making sure to make a firm finish at the end of the sewing. The top stitching on the back went generally lower than at the front.
When I tried it on the arm holes were very gappy and the overall shape was still to wide at this point so a took in the side seams to fit more closely under the arm, flairing out to run into the original sideseams towards the bottom. (This picture is upside down, arm holes at the top)
I then finished off the arm holes by using a piece of opened up bias binding (you could use some ribbon- cross grain is best) and pinning it with the edges together and front sides facing from the bottom of the arm hole all the way round. This was machined on following the crease of the fold line on the bias tape. The next stage was to turn the bias tape inwards so that it was on the inside and no longer visible then pin (baste?) and top stitch around the edge to neaten off. Hopefully these pictures will help that to make sense.
In part two I will describe how I finished off the dress.