Old Shame: On a late-'80s radio interview, John Cleese spent several minutes thoroughly denouncing the show and said he thought it was a waste of his time to be doing it. In his 2015 autobiography So, Anyway, he said that his mixed view of the series was the audience's fault for laughing and cheering so loudly whenever a recurring character or catchphrase was recited (a practice not unique to ISIRTA and one that Cleese deplored even then), leading to the overuse of such devices at the expense of fresh ideas.
Talking to Himself: Occasionally, and usually Lampshaded when used. A common situation was a conversation between recurring characters Tim Brown-Windsor and Lady Constance De Coverlet, both played by Tim Brooke-Taylor. One episode took it Up to Eleven by adding in Lady Constance's identical twin sister.