How to be diplomatic

How I wish there was some self help book on being diplomatic. I am either straight forward to the point where the other person gets offended or I keep things to myself. There sure is a way in between these two. Just that, I am lost in my attempt to find it.

There has been many instances in my life where keeping quiet would have helped me and equal number of instances where I should have spoken up( That would have saved me from taking all the suffering/blame)

I was as straight forward as one could get .It did hurt many around me. So, I started trying to notch it down a little. Sadly, now I am at another extreme where even if I want to say something on someone's face I cant do it:-(

Thankfully, I am married to a person who is good at being diplomatic. He doesn't do injustice to anyone and he doesn't let someone else treat him with less respect. I really adore that quality in him.

I remember an incident when we had been to smoky mountains, we were watching fireworks. A couple were standing in front of us and we were sitting. Everything was fine, until the girl decides to move , thus blocking our view. My husband went and asked the guy to move a bit so that we all can watch the show comfortably. He responded rudely to say that we should stand up to watch the show. Now, I asked my hubby to keep quiet and we got up. But, later he did explain to me why it was not right and we should not let others have their say if we are right. It was a small incident but I do remember it whenever I keep quiet in spite of being right.

I hope I will find the courage to stand up when I am right, apologize when I am wrong and treat others just the way I want them to treat me.