There a number of techniques which are incorporated into this aspect of Art. There are also various apps and workshops that can be used to create the photomontage including Paint, Photoshop and other Digital imaging websites.
Francis Picabia, Dada Movement, 1919 – It is the wiring diagram of a Dada alarm clock (made in Switzerland in which historically plots the flow of the current of modern art, from Ingres to Picabia's own Dada magazine.
Animals and people mixed. This gives the bird a sophisticated look with the tea cup and long jacket. The bird looks bright against the faded background and its beak looks like the main stand-out colour among the cooler colours.