Day 1 in Florence is Accademia and Renaissance walking tour(Brunelieschi Dome, Baptistry Doors)
Day 2: Uffizi We will arrive a day before the tour begins and wondered what sights/museums/moderately priced restaurants we should we do on our own? We also have an afternoon "on our own" in Florence, so we are considering Siena. Any suggestions
Cathy, For your "free afternoon" in Florence, I'm not sure the time will be adequate for a trip to Siena. While it's certainly feasible, you wouldn't have a lot of time for exploring Siena. Your Guide will probably offer a few suggestions for ways to use the "free time". One possibility for a short tour in Florence, would be to take the Bus up the hill to Fiesole. As I recall, one of the Hop On / Hop Off Buses travels there. It's a beautiful and "classic Tuscan" location, with old Villas and olive groves. Have a great time on your tour!
It's actually a free afternoon and evening. Would this be enough time to see Siena?
If you are not scheduled to go inside the baptistry, I would spend some time in there. It is beautiful and stays very cool on a hot July day. Try to get up high somewhere, anywhere. It's a wonderful perspective to enjoy the city. Cross the Ponte Vecchio and head to the left along the river. I really don't think you can do Siena justice with just an afternoon. I'd stay in Florence.