Cut a t shirt in half vertically and just below half diagonally.
Fold over and pin/tack stitch all raw edges so they are even and ready to sewn on the machine
Put this to one side
Cut the material from the bottom of the original t shirt into 4 equal pieces (cutting in half and half again is usually easiest)
You should now have 4 strips
Fold these strips in half and pin the longest edges together and sew
Pin 2 pieces to either side of the t shirt, where the shrug would open
Pin the left over strips to the bottom of the t shirt (the hem)