Some words are bitter, others are sweet, some simply melt in the mouth. The thing is, we generally only think about the words we use conversationally when something goes wrong.
Try this: next time you have something important to say, before uttering it, write it down. When you are satisfied that you have captured it, and you message is clear, read it out loud to yourself a few times. Does it flow? Does it feel natural to say the (written) words you have chosen? Does anything need changing?
Once you have done that leave it for 24 hours, then put yourself in the position of your intended listener(s). Attempt to see how they will hear it. Does it truly convey (and will it be understood as), the message you intended?