When I have the house to myself, the first thing I do is pour myself a tasty beverage and clean the house. My DH is a clutterbug, so it's the one time I know that when I clean it it will last for more than a day. In the evening, I'll either re-watch some of my favorite movies, or watch some of the trashy cable TV shows that I know he hates but I secretly enjoy. During the day, I'll do pretty much what I would do any other time, but I sleep in longer and don't have to worry about our schedules matching up.