These family affairs provided a lot of great photos in the early 1900s. This photo from 1914 from the State Library of Queensland is a great example!
Meanwhile, in big cities, larger companies were trying to corner the entire market on milk delivery. This 1905 from Montreal shows a full-scale operation from the Guaranteed Pure Milk Company delivering throughout the city.
Meanwhile in the smaller cities, some of the milkmen decided to expand operation to cream AND Ice Cream as well. Here's a great photo of what is a hybrid milk cart and ice cream truck.