I have learned over time though education, sports, or work that it is important to provide open and honest information to others. It is often a bit difficult to share or hear it, but saying what you mean is in fact the only way to get your point across. Or course, you don't have to be mean while doing it.
And for that matter, you don't have to assume someone is being mean when they tell you something constructive. Let's try this...the next time that you balk at saying what you mean, try to be straight about it. The next time someone is straight with you, graciously say thank you. Where would that get us as a society? Would we be better off, or would the world implode with honesty and conflict? I would be willing to take the chance, as long as we say it nicely.