The last of four forms of right speech identified by the Buddha is useful speech. We could start practicing this principle by affirming the intention: “I undertake the training rule to refrain from useless speech”. In Pali the word for useless speech is samphappalapa, which has an onomatopoetic ring, like blah, blah, blah.
Useless speech is talk that we generate simply to fill the air, often because we are uncomfortable with silence. Everyday greetings do not fall into this category, but are a way of smoothing relations with all whom we meet. For superficial interactions, politeness is beneficial (add kindness at will), for example, “Good morning” or “Have a lovely day”. If there’s time for more, a neutral topic can be found. But if a real conversation is happening, we can guide our speech away from silliness. If we ask “How are you?”, we stop and listen for a meaningful reply, with our eyes and ears. This is an opportunity to connect with another living being, to learn her/his present state of mind.
The ultimate form of useful speech is talk about the Dhamma; hearing, thinking and speaking with wisdom. Is there dukkha here and now (ours or others’)? Are there any words we can think or say that will alleviate or contextualize the dukkha in a helpful way? Can we bring metta (boundless loving friendliness) or karuna (compassion) to bear? Is there some joy that we might share (mudita)?
With all forms of right speech, we begin by NOT expressing the thoughts that motivate them (false, divisive, harsh or useless thoughts). We just let the words stay in our mind without being verbalized. If we don’t say them, they will fade away on their own. While we’re patiently waiting for negative thoughts to pass, we might consider whether we have anything wholesome to contribute. Silence, or keeping our peace, is sometimes the best option. If we incorporate thoughtful pauses into our conversations, we may not have the last word, but our words with be worth considering.
Note to self: more listening, less talking.
From Sn 3.3 translated by Laurence Khantipalo Mills, edited by Bhikkhu Sujato (https://suttacentral.net/en/snp3.3):
Only that speech should be spoken
from which harm does not come to oneself,
nor torment brings upon others—
this truly is speech that’s well-spoken.Speak only those words that are kind,
the speech that is gladly received,
so whatever one speaks to others,
conveying no evil, is kind.
The Buddha's Advice to Laypeople 
Hi Lynn,
Thank you for this post and for all of your sharing of devotion to the Buddha. This is a very relevant topic and filled with plenty for all of us to digest. But “and how” do the Buddha’s teachings on this topic work, and it is so true is what you have shared that you reach a point that eventually your mind becomes unconsciously competent. When derisive speech or non Samma-Dhitthi words fall upon our ears one day and there is no retort popping into your minds, you suddenly realize you have in fact crossed over to the other side, when your mind just has stillness to offer in return, and it all happens ever so gentlyv and ever so quietly. Your thought processing and response generating tree has bore fruit. You give a little chuckle, you smile a little smile and you utter to yourself or think, “I’m there, it really happened.” You realize that you have reached that goal. It then happens again and again, and still we become amazed that our practice is working as was told to us how it should. And one day we will become an unconsciously competent as well. That is where we have no reaction to another person’s improper speech, other than to recognize that the other person spoke unkindly or harshly and then we are there again, just stillness,