A simple, useful rule that will change your life forever: only say things you mean and mean every word you say.
I cannot be the only person that is fed up with people who say one thing and then make no effort to deliver upon their words. When you create a reputation for yourself that your word is your bond, you have struck gold already!
So, the next time you open your mouth or make a promise to a customer or friend alike, be sure you are ready to fulfill what you are saying. If you fail to get it done, make it clear exactly what went wrong and if it can be fixed and all that.
I cannot be the only one who no longer takes people at their word after series of disappointments.