You could spend the rest of your life fishing the Soane.
I can recommend the following areas: -
1. Glannon, night fshing zone. This is a beautiful part of the river. Lots of fish with the odd biggie. Not too many Cats also.
2. Verdun sur le Doubs. Campsite, river starting to get big here. Lots of carp plus lots of biggies if you get lucky. Lots of Cats and some cracking zander to over 20lbs, my mate had a 20 1/4lb zander!!!!
3. Chalon sur Soane. Lots of everything. Very popular with the french carpers. I was at an Enduro fished on the town stretch in 2005 and the number and size of fish that were caught were amazing.