BardStephenFox said:3x5 cards that you keep with your gaming stuff. When a PC uses an item, you might need to find the card, but then the player doesn't know how many charges are left, etc.
this is exactly what I was goimng to suggest. You can put what the item is, what it does, who owns it and how many charges it has left. If it has charges, put a number of boxes on it equal to the charges and mark them off whenever used.