Materials:
- large men's dress shirt
- matching thread
- scissors
- pins
- sewing machine
Step 2: Put the shirt on, buttoned all the way to the top, and mark with pins where the shoulder seam should be and where the flat yoke in the front will stop. The shoulder seam should sit right above the knobby end of your collar bone and the yoke should stop about an inch down from an imaginary line drawn between the tops of your armpits. (Figure 1)
Step 3: Take the shirt off again and lay it out as flat as possible. Make sure the seams are straight on the sides and the shoulders lie flat. Also, make sure that the pins you used to mark the shoulders match.
Step 4: Using pins, or a fabric pen, trace a line straight across the front on the pin that you used to mark the bottom of the yoke. (Figure 1)
Step 5: Using pins, or a fabric pen, trace a line down from the pins you used to mark the shoulders, mimicking the curve of the current shoulder seam, until they reach the line across the front.
Step 7: Take one of the existing sleeves and slip it up up your arm until it sits at the length you wish. Mark where the top of the sleeve hits that same point on your shoulder. Using pins, or a fabric pen, trace a line down from the pin you used to mark the shoulder, mimicking the curve of the current shoulder seam, and cut along this line. Lay the shortened sleeve piece on top of the other sleeve and cut to the same length. Your shirt should now be in pieces like this: