Step 1: Supplies
-Duct tape: I used just over one roll for my friend, who is pretty tiny. You should probably have at least two or three rolls on hand.
-Shirt or plastic garbage bag (person sized): Whichever of these you use, it should be as long as you want your dress form to be tall
-Newspaper: lots for stuffing. I used almost two whole newspapers from Thanksgiving, so they were even fuller than usual.
-Permanent marker/pen that can write on duct tape
Step 2: Prepare your model
If you're using a shirt to make this dress form (Note: it will get cut and become one with the form), skip to the next step. If you're using a plastic bag, tun it upside down and cut a hole in the bottom just big enough for your model's head to fit through. Have her pull the bag over her head so you can judge how big & where you need to cut your armholes. Cut circles in the bag where your model will put her arms through. Try to keep the arm holes as close-fitting to your model's arm size as possible, as this will make constructing your dress form easier later on.
***This is a good time to pause for a trip to the bathroom. Soon your model will not be able to sit or move around easily without possibly damaging the dress form in progress.***