What is the preferred practice for introducing a coined expression in writing?

Using double quotation marks the first time a coined expression is introduced is the preferred practice because it provides clarity to the reader about the term's special or novel status. When a writer introduces a unique phrase or expression, quotation marks signal that this is a term being defined, explained, or highlighted, drawing the reader's attention to its significance. This practice helps establish the term's context and allows readers to understand its intended use within the text.

After the initial introduction, the absence of quotation marks in subsequent uses indicates that the term has been integrated into the text's discourse, and readers are expected to understand its meaning without needing to be reminded each time. This approach enhances the readability of the writing since excessive use of quotation marks can disrupt the flow and make the text cumbersome.