Buster Keaton is someone all animation students should look at, Keaton’s use of camera angle’s and camera place made him one of the best comedian of his era. In Keaton movies, the camera was often further back this is because Keaton like to show the motion of a joke often consisting arc’s triangle and square’s. Keaton understood that the strength of a joke was the setup, not the punchline.
Keaton was also known for the lack of title card’s in his movie the average and the time was over 100, Keaton never used more than 50, Keaton’s relied on visual gags to progress the narrative.
Something else I think can be learnt for Keaton and something I could learn from is to not clings to idea Keaton often said if they didn’t get in on the first try they cut the gag.