Go nuts, surprise your players, and have fun. Write out some history on each item, where it was made and by whom, when it was last seen, famous owners, etc. Use more detail for the more valuable and older items. Jot down notes on famous battles fought with the item, people killed by thieves wanting it, legends surrounding its creation, etc. If one doesn't get used, use it later on a different item.
Items can lead characters to explore ruins in search of related items.
Generally, the more powerful or valuable a find is, the more trouble it will cause the characters. Placing the treasure with care is another consideration. These questions will keep you from creating a ridiculous situation, or at least you will have a reason for the ridiculous situation. Questions and comments are most welcome.