For some, the correct word is "exercise", for being nice and kind sometimes doesn't come easily for some people. That doesn't mean that they can't be nice or kind, but by not exercising, actually make an unconscious choice to be snarly, callous, or indifferent. These folks tend to allow their speech to be full of complaints, bitterness, and contention. To others, being nice is second nature. You enjoy being around those people, for they are always full of compliments, praise, and encouragement.
A kind word can go a very long way, but a word with an attitude can be like building a brick wall between two people, or even around yourself. With some, it often feels like a full time job of dismantling stacked bricks.
I am going to try to be full of kind words today. I am going to try to not complain about things, or even about those who aren't full of kind words. Lord, help me to be more like Jesus.