How to Draft a Garter belt
Now fold the rectangle in two to find the Side Seam, and in two again between the side seam and the ends to find the position of the garter elastic extensions. Your rectangle will be divided into 4 equal parts.
Mark this distance out from each dotted vertical line. You should have 6 marks in all, each (in my case) .75″ away from the vertical lines.
Connect the 6 marks to the bottom of the vertical lines at the hip line. These are your dart legs.
Cut along the black vertical lines B and SS and fold so the pink dart legs align and the darts are closed
If you imagine the full length garter belt (instead of just one half) this is what it looks like. You could keep it in one piece or you could break it into smaller sections to save fabric or to provide some interesting detail.