Film was expensive to buy and develop. Much of the aesthetic of New Wave films came from the need to make films as cheaply as possible. French New Wave filmmakers often shot their films using old, 16 mm, black-and-white news cameras. The cameras were hand-held and allowed the filmmakers to move them more easily. Because lights were just as big a cost as film, New Wave filmmakers shot outside in natural light to reduce the cost of renting lights. Frequently, non-actors were used along with professional actors.
Classical French literature and films were highly structured with strict narrative styles. The films of the New Wave broke with that tradition. Although most of the films followed a narrative story line, there was no attempt to create a bond between the lead character and the audience, as would happen in a traditional adventure film. New Wave stories were more likely to embrace existential themes than they were to tell a traditional story. Their central characters were more frequently in realistic situations than they were in fantasy scenarios.
Many narrative styles from the French New Wave have become commonplace in commercial film-making today, but they were startling and innovative when first used. New Wave cameras first broke the "rule of 180," meaning they were the first to circle all the way around a character or object. Characters stepped out of the story to address the audience -- another innovation of the French New Wave. Often scenes were improvised rather than scripted. Actors sometimes interacted with regular people in the street and the scenes were incorporated into the film. The techniques were in reaction to the films of Hollywood in which everything was controlled, staged and lit perfectly.
Italian neo-realism took to the streets to show the harsh conditions of post-World War II Italy. French New Wave filmmakers were inspired by this kind of story-telling and worked to incorporate social themes into their stories. They chose to tell stories that showed the darker and less flattering sides of society and humanity. There were hardly ever heroes or villains in the French New Wave, except for the concept of the social strata itself.