I make frequent trips to Edinburgh. You will be doing a lot of walking, and the Royal Mile is cobblestone. Wear comfortable shoes or hiking boots. I went out on New Year's Eve all decked out, including ghillies, but after the first pub stop, I returned to my hotel to change shoes and was sure glad the rest of the night that I did. I changed into semi-dress black shoes with good soles, and they looked fine. Besides, everyone is drunk after awhile and everyone looks good then!