You should always have Amitoi Expeditions going, whether you're looking for salt or not, but when you are in need you should make sure you're sending your little friends on expeditions that offer this ingredient.
Many enemies in the world can drop Salt, but you may be surprised at how rare it can be. While there are various spots you could farm for the ingredient, your best option is almost certainly Windhill Shores.
Collection
[
|
...
]