It's amazing how often we don't say what we mean and mean what we say. Think of what you said when your husband supposedly cleaned the house, or when someone gave you fruit cake for Christmas, or when your friend's new outfit looks like something out of a Barnum and Bailey garage sale.
Then, the old saying, "if you can't say something nice, don't say anything at all" comes to mind. That's when you have to weigh how your response would best help the person asking for feedback or a pat on the back.
The fruitcake, I'm sorry to say, you're stuck with. It's the thought of giving that counts. Your husband tried, and later on, you can throw in a few remarks about how you clean.
But, the circus outfit is another story. If your friend looks ridiculous, how much of a friend would you be if you let him or her wear that clown outfit out in public? If the outfit is for Halloween or a child's birthday party, it's not an issue.
"I really think it would be best if you considered a different outfit to wear to the office party today" instead of "Wow, is that outfit the stupidest thing I've ever seen!" is a bit easier - and more helpful - to take as genuine feedback.
There are other times when "say what you mean, mean what you say" needs consideration too. If someone asks you directly for an honest opinion, give it. Take care with your delivery, but do not dilute your honesty by beating around a bush. Check your "pulse" by taking note of what you think and feel, determine the true reason for your reactions, and own what you think and feel as a main component of your honest opinion.
White lies are still lies.