Cut out the pattern from the scraps of sweaters.
Turn right sides facing and hand stitch (or machine stitch) the body curve (along the top) together.
Add the bottom panel to the opening at the bottom of the mouse. Leave a small hole along one side.
Turn and stuff the mouse.
Close up the hole.
Add ears. Fold the bottom edges of the ears towards the center. Then sew onto the mouses head that way.
Add the face and tail. For mine, the eyes were just French Knots... and the tails are braided embroidery thread.
To hang on the tree, take a piece of embroidery thread and put a hoop down the back of the mouse, starting at the head and ending half way down the body. This makes it hang correctly on the tree. If you put the hoop in too small a space, the mouse leans forward, and it's ears make it front heavy.