The subject came up of collecting and conserving items in RPGs. Expendable items are problematic because it's in a lot of players nature to not use such items in order to save them for when they are really needed, but then these players end up never using them in the first place.
My first thought was to eliminate items in the traditional sense. Rather, items would be crafted/created by spending mana/spell points or possibly combining material.
Ideally the spell system would be re-worked to compensate for such a mechanic. Such as, some enemies would reward with more mana after eliminating them than others.
Then, in theory, the player could choose to cast magic during a battle to fight and then after a battle in order to heal, which would drain mana against tough opponents that don't reward with much mana. Or, the player could choose to conserve mana by fighting weaker enemies that reward lots of mana, then use the excess mana supplies to craft magical items to be used in battle against tougher enemies.
Some mechanic like this would also take away some of the random-drop factor with traditional items, and would put a curve on the use of currency for expendable items. Grinding in certain areas in order to fight certain monsters that drop specific items random is not very fun, it's a grind. But with a crafting system the player could be given a certain level of control over what items are made. Very useful items could be balanced with some form of value system. That would also enable players to choose to craft a very mana-expensive item, banking on the risk that they won't be needing mana for a while until they regenerate from the cost of creating a heavy-duty item.
In order to further encourage item use, items could be given bonuses to regular magic. Such as, magic could be very standard, but magical items could have the property of gaining potential critical hits or having some kind of affinity bonus.