Start being more generous with your opinions, and you'll start making your relationships a lot more meaningful. You can't underestimate a person's ability to accept constructive criticism: they want to be told the truth, just like you do. And few people are as good at couching their negative remarks with tact and charm as you. So don't hold back when saying what you really think about their project or idea. They're counting on you to give it to them straight, so don't let them down!