Start at the front

Starting with the orange 'mouth marking' area (using the orange yarn tail as in the photo), sew the head to the torso chest. By starting the connection here and keeping the body aligned you may avoid the crooked head result. Pause where the mouth marking ends.

Next, start connecting the area next to the orange mouth-marking. Sew with brown yarn  in the opposite direction of the orange area.  Pause around where the back begins.

The Other Side: 

Use a different brown yarn tail to sew together the other side of the head to the torso. Also, fill in any stuffing gaps and dents as you go along prior to completion.