Agritourism in Tuscany or Umbria?

Google 'Villa Arnilu" near San Gimignano

1. Do some research on the villages and towns you’d like to visit. The top hits are listed in the websites linked at the bottom.
2. Plot your intended destinations you’d like to visit on a map
3. Find an Agriturismo that is central to the locations you want to visit using any websites, such as: www.agriturismo.com www.agriturismo.it www.agriturismo.net
4. Locate the exact address of the Agriturismo on Google Maps and calculate the driving distances to your intended destinations. This is important because some farmhouses may look well located, but are actually hard to reach through winding narrow roads (sometimes partially unpaved). My suggestion is to find a location from which it is easy to access the two main freeways: Siena to Florence, or Siena to Perugia. The latter is better if you want to visit Umbria and Tuscany from one location, because distances may be a factor. If you have several days at your disposal, it may be advisable to choose two bases, one in Tuscany and one in Umbria. It’s hard to visit both regions from one place only. For example the town of San Gimignano suggested by Gordon above is great for Tuscany, but it would be quite a long drive to visit Umbrian towns on day trips from there (at least 2 - 2.5 hours each way).

Best towns:
https://www.borghiditoscana.net/en/
https://www.expedia.it/vc/magazine/idee-di-viaggio/il-belpaese/borghi-in-toscana-15-gioielli-medievali-da-visitare
http://paradisiparalleli.com/2014/09/i-10-borghi-belli-toscana/
http://paradisiparalleli.com/2015/03/i-10-borghi-piu-belli-dell-umbria-da-visitare/

Check out my neighbors' place near Perugia: Google "Ca'Mazzetto" in Valfabbrica. It's an organic farm with friendly dogs and sheep. They're multilingual, have a pool and self-catering apartments. (Note--I have no financial interest, it's just a beautiful place.)

In Tuscany, we have stayed at Poggio Etrusco in a delightful apartment that made a good base for going to Montepulciano (Poggio Etrusco is right outside the town) as well as Montalcino and the Abbey at Monte Oliveto. Pamela and Johnny are delightful hosts and will serve you a nice breakfast as well.

In Umbria, I have stayed in Rebecca Winke's town apartments but have been eyeing her lovely agriturismo, Brigolante, outside of Assisi. Great location!