Most carvers sketch out the parts of the carving on the wood before carving them.
Notice that in this sketch the right side of the face is about the same as the left side. This is an example of symmetry. The sketch lines of this Santa represent where Stop Cuts will be made to define the various parts of Santa's face.
To complicate the process of achieving symmetry when carving the Santa face we often times cut off these sketched lines when starting the carving. When this happens we are usually instructed to redraw the sketch lines.
Try roughing in one side first while leaving the sketch lines intact on the opposite side, then do the "other" side. If you don't, you probably should resketch this other side to match the first side you roughed in.