If you have bad news to deliver, be honest. Honest communication is what fosters trust in a relationship.
“I’m sorry, but it just isn’t going to work out for you to be promoted now. There are some specific areas where other candidates were stronger.”
“I’m sorry, but I’ve decided not to buy your widget because I found one that is cheaper and still does what I need it to do.”
To improve your business, you need feedback. To improve your skills, you need feedback. If someone chooses not to buy your products, ask why. If you aren’t promoted, ask what you need to do to be considered in the future.
Asking gets you information. Information is a first step towards creating change. Information provides you with choices on what to do next.