When you notice bad stuff coming out of your heart and mouth, ask God to help you with a “re-do”. Form a better response with the Spirit’s guidance, and re-do the interaction.
Memorize and meditate on Proverbs 16:24 - Gracious words are like a honeycomb, sweetness to the soul and health to the body.
Create space with a group (family, friends, coworkers) to practice affirming and blessing each other.