By way of exercise I copied a detail of a watercolour by Onorato Carlandi (Roma, 1848-1939). There is a beautiful exhibition about his watercolours in Palazzo Braschi (Piazza Navona), Rome. There are two rooms: one with older work made during his stay in England and the other room with work about Rome and the roman countryside. It runs until the 3th of july. If you are in Rome and you like watercolours I think this is a must-see! I went twice and bought the catalog.