Miscellaneous: Although things tend to cool off at night, if you're an American and used to air conditioning, you may find that it is well worth your while to bring a small battery-powered fan with you, or to purchase a slightly larger fan which has the appropriate plug for Italian current. I brought two of the former and we never did get around to buying the latter -- but we certainly would have been much more comfortable had we done so, and at minimal cost.
Miscellaneous: Given the paucity of laundromats -- I never found one -- it is probably wise to bring along a small bottle of laundry detergent (though shampoo will do in a pinch), clothes pins and laundry line. You can wash out your "smalls" each night in the sink, and periodically launder larger items when you have access to a bathtub.
Miscellaneous: Our villa in Volterra included bath towels and hand towels, but not what we Americans call "wash cloths" (a small towel used to wash one's face). Luckily, my friend had brought a supply which could be left behind in each city, and I brought Olay's excellent cleansing tissues because that's what I use back in Rhode Island. But if you're younger than we are and dislike using a corner of your bath towel to wash your face, you might think about packing something you wouldn't mind discarding after your visit.
Miscellaneous: A word to the wise: many Italian windows are unscreened. This can come as a very unpleasant surprise in warm weather if you failed to pack insect repellent. Having done so, I did not investigate whether it was available in Italian pharmacies. Our rooms came equipped with fly strips and citronella candles, and that was insufficient.