My favorite way to explain something new - is to compare it to something very common or well-known. For example, I explain some music production processes to my friend, who is a professional illustrator, through the comparison with the drawing process. I guess the easiest way to explain the idea of bitcoin to a person, is to compare it to the current banking system, and then to show all the advantages of blockchain technology and the examples of it's usage in the fields where this person works.
That's my way of spreading Bitcoin knowledge  Also I spread the knowledge to Russian-speaking community by doing voice-overs of some crypto videos (I do translation from English to Russian)