McGee popularised the use of paint drips in urban-influenced graphic design, as well as the gallery display technique of clustering paintings. These clustered compositions of pictures are based on similar installations he saw in Catholic churches whilst working in Brazil. He was an early participant in the practice of painting directly on gallery walls. These characteristics are crucial to the installation he created specially for the exhibition Made by... Feito por Brasileiros at Matarazzo Hospital. His work expresses an oppressive but vibrant reality influenced by American West Coast culture, with its pessimistic vision of the urban experience, which McGee describes as “urban ills, overstimulations, frustrations, addictions & trying to maintain a level head under the constant bombardment of advertising”. His paintings are iconic images in which the central figures dominate abstracted, colourful backgrounds. For his exhibitions, the artist also paints portraits of hoboes on their own empty liquor bottles, on dented spray cans and on wrecked cars.