She tried to 'smooth things out' [=end an argument or disagreement] with her daughter-in-law, but the damage was done.
They 'smoothed the way' for a quick end to the dispute. [=they made it easier to achieve a quick end to the dispute]
Her time at college wasn't all 'smooth sailing'. [=she had some problems/difficulties during her time at college]
(..) I know that you didn't always approve of the means, but we both know that the end result was always right. You're still the best smooth talker I know. Use it now. Talk your way out of this. Settle. Because if this goes to court, there are skeletons to be found. They won't find them. (..)2011 TvShow: Suits Title: Rules of the Game Season: 1 Episode 11