This is indeed a great topic!
Some weeks ago there was an article about Jean-Claude Ellena in the german paper 'Zeit'. It described his career, his approach to fragrances and his successes and defeats (searching for 20 years for someone to buy his green tea fragrance and then seeing that ckone by another parfumeur becomes one of the best-selling fragrances ever - Ellena says this other parfumeur is not his best friend;-). He is now under exclusive contract under Hermes, though there is a clause in his contract, that he may engage another parfumeur in case he has a creative black out and hermes wants a new fragrance. Ellena fighted for this clause! In the article he also said, he had a hard time to create Un Jardin sur le Nil because he just didn't find anything that smells like that until he found the green mango(I think it was that, could be wrong, read it weeks ago).
Before his contract he tried to sell his fragrances and fragrances companies asked him to make certain perfumes.
Interesting sidenote: He almost never wears fragrances, only at high festivities!
Hope someone else can give us more insight on this topic!