Starting by wrapping a piece of construction paper around the thigh, cutting the piece into the shape above. Cut an arc on the bottom right corner to allow the knees to bend (more leg articulation).
Next, cut the middle and top piece off like above.
Reattach them to the thigh piece as so. Essentially, this step makes the thigh piece hug more to the hips, giving it a more fitting feel.
Next, make an inner thigh piece (yellow) that will attach under the outer thigh piece.
Plastidip, prime, and paint.