For my trip to Santiago de Compostela I have chosen a different route to the South of France than on my way back: "Langs Oude Wegen" (= Along old roads) and for the return trip the well known "St. Jacobs bicycleroute - part 1, 2 en 3".
Main reason
for doing this is that I have already cycled part 1 to Tours some years ago (right thru Parijs to Tours and the way back via Chartres, Rouen, Honfleur, Belgium coastline).