Im a hoarder, so I use 4 retainers. Each time i get a new retainer its empty for a short time then gets filled super quick.I have 1 for food ingrediants, another for ingots (Actual ingots leathers, lumbers, etc), the 3rd is gear and materia, and the 4th is raw mats such as ore or logs.
I lowered quality of all my duplicate items so that cleared up some space but i refuse to throw away items, cause what if i need it?