Begin by unrolling the toilet paper about 15 times. Then roll the paper back up, twisting the TP as you roll. The goal here is to create a rounded shape, so keep that in mind as you roll the paper back up. Tuck in the end to secure.
Cut off one sleeve from your sweater. Cut straight across from under the arm. Trim off the cuff of the sweater. Your sleeve piece should be 12-13 inches long.
Stretch the sleeve out wide, and place it over the toilet paper so that a few inches of sleeve sticks out on either side of the toilet paper. Reach under the sleeve and smooth out the toilet paper roll if needed, creating a rounded shape.
Tuck the extra sleeve inside the toilet paper roll on the top and bottom of the pumpkin, straightening out the sweater if needed.
Tie a ribbon around a stick. Trim ribbon if needed.
Place stick inside the toilet paper roll to create a stem. Decorate with twine or leaves as desired.