One of my favorite coffee-table books is called Extraordinary Touches for an Ordinary Day, by Jo Packham, which is basically about putting together sweet guest rooms.
One of the things mentioned in the above book was adding a small carafe and glass. I've been looking for one for years and finally found one at the big Pultneyville Community Sale (which seemed to have been put on mostly by people like me; antiques dealers who were no longer in business and selling off their former stock--cheap!)
I found this little hand-painted beauty.
My sister-in-law comes to visit every now and then. I hope she enjoys our guest room. I've tried to make it pretty and comfortable. Now, if she gets thirsty in the night, she won't have to get up in search of water.