Formal:
* Mon amour, mon cher/ma chère: This is a more formal and affectionate way to address someone.
* Ma très chère/mon très cher: This is even more formal and emphasizes the depth of your affection.
Informal:
* Mon cœur: This translates literally to "my heart" and is a very endearing way to call someone "love".
* Mon chéri/ma chérie: This is a more informal way to call someone "darling" and is often used between lovers.
* Mon amour: This translates to "my love" and is a very common way to express affection.
Other options:
* Je t'aime, mon amour: This means "I love you, my love".
* Tu es mon amour: This means "You are my love".
Note: The gender of the person you are addressing will determine which form you use. "Cher" is used for men, "chère" is used for women.
Ultimately, the best way to say "love darling" in French depends on your relationship with the person and the context of the situation.