Do not let your words be mindless fluff floating in the air. Your words should be able to be planted and produce fruit for others to enjoy.
I once had a professor who choose her words very carefuly. Whenever I spoke with her I could tell, by the way she spoke, that every words was chosen with care. I try my best to be careful with what words come out of my mouth!
Like I tell my students...your tongue is a powerful weapon, you have the power to build someone up or tear someone down!