I just made a Private Tour with Alice Salvagnin of Milan Private Tours.
She was extremely informative before the visit with emails, very passionate about Milan and its history!
We visited the Duomo cathedral with the inside, Galleria Vittorio Emanuele II, La Scala theatre Opera House, Brera area, Sforza Castle with internal courts and the Last Supper (she was able to provide tickets with short notice). After the tour, she wanted to be sure we were going to contact her in case of any information and she made reservation for dinner at a local restaurant. It was a great experience! We also found out many of her "hidden gems", charming and suggestive sights of the historical centre, not very famous but extremely interesting (as a Bramante church few minutes away from the Duomo cathedral, a crypt of the XIV century right away behind the Duomo cathedral). Absolutly recommended!