Back when I was playing Neverwinter Nights, I tinkered with designing some items for my character. In that game, the items you could use were limited by your character level (so a 1st Level character couldn't wield a +5 Holy Avenger right out of the gate), so I spent some time tailoring some weapons to my current character level. There were points for various attributes, such as accuracy, damage, healing ability, secondary damage (think flaming sword), other spell abilities, etc.
While I'm NOT suggesting character level minimums for items, having a mechanic in place where you can make a custom item (Staff, Sword, etc.) that has varying attributes for varying point costs might be nice. AND, items of a certain 'level' (read: cost) have a maximum number of points that can be incorporated. These 'item levels' would come into Play utilizing the tech levels we have now (where more magical items become available as the tech level is increased).
So, in Elemental terms, as an example:
Minor Staff Of Channeling: +1 Accuracy, +1 Mana per Turn, +1 To Dodge. Or, +2 to Mana (or Accuracy or Dodge) only
Staff Of Channeling: +2/+2/+2, or +3/+1/+1, or a single +4
Greater Staff Of Channeling: +3/+3/+3, or +4/+2/+1, or a single +5.
This wouldn't be THAT much different from, say, designing ships in GalCivII, where you have a limited number of hull points to stuff things into, and that stuff comes in different sizes. Think of using the ship design interface, but instead of designing a ship you are designing a magic weapon... or perhaps a 'suite' of magic items/abilities for your character. This might also be a way to incorporate character level into character design (i.e. you have 'x' number of magic points for items, based on your current level. The various magic items would have a 'magic' point cost, so you'd have to be a little more picky about which items you want active at any given time. That might be a litte TOO immersive for some players, though.
You get the idea. This would go hand in hand with not just piling on any and all items you can get your hands on, i.e a limit on the number of rings and amulets you can use, weapons are already limited to 1, perhaps two if Dual Wield ever shows up, so that having these specially customized items would have more value. And this would give those that like to crunch numbers more numbers to think about!
This just made me think of a 'Character Design Interface' screen, where you have a Character Portrait to the left of the Shop items, and any items you already have show up on your character, and mousing over them shows what they are and how much of a bonus they provide. That way, instead of wondering if you needed Greaves, for instance, you'd already see the Greaves (or Travelling boots) on your character portrait. Basically the same you see on the Equip interface now, but in the Shop interface as well. Someone else suggested something similar already, so that's an idea for another thread.