One of the more popular techniques in speaking is to quote a famous person. “As Einstein said…blah, blah, blah.”
Avoid it if you can. It often comes across as stiff and condescending, it might be slightly off of the target message you want to give and it’s always a diversion. Instead, put the time in to think about what you wanted to communicate by using that quote and how you can say it better and more personally in your own words or with a story.
Go through your office and donate all of those Bartlett’s Familiar Quotations books you have to charity.