Realism
An example of realism in Bonnie and Clyde would be the verisimilitude that comes with the violent scenes. Before the New Hollywood era, heavy uses of things like blood were uncommon in films, so Arthur Penn challenges this by presenting a realistic depiction of what would have happened to characters when shot at.
Tone
Suspense is built in the final scene of the film, with the fast paced editing between shots creating a sense of panic for the audience before the eventual firing of the guns.
Visual Style
A common camera shot during the French New Wave era was tracking shots. One scene in which these are used in Bonnie and Clyde is the scene where Clyde exits the car to run after Bonnie. The camera follows the vehicle as it moves, as opposed to remaining stationary and having the car go into the distance.