It should be possible to hover an item over another item to see what it combines into rather than needing to put an item onto a champion first and then hover the other item over the champion. Additionally, the ability to combine unused items should be available as well. It may also be a good idea to streamline the space where items drop so people aren't clicking on wrong items and dropping things in wrong places.
Riot can definitely improve the user interface for items. As far as combining items that aren't currently being used, you can always combine them on a throwaway champion on your bench or buy one. Combine the items on them then sell and you have your completed item on the bench. As far as knowing what certain items make, I agree there needs to be a better system. Some kind of in-game store or reference would be a great solution. Simply hovering items over each other like you mentioned would also be effective as well. I think they'll make improvements in that regard before the game leaves beta.
Im confused. You can already preview item combos, so Im not sure what you're asking for
I think riot should put a small list in the top right corner telling u what items you can make with the items you have where you just have to hover your mouse over the item's name and it would show you the item combination.
