I learned the following truth the hard way:
Children will learn more through observation than pontification.
This, spoken from a “grand pontificator!” Most of the time your children don’t want to hear your reasoning behind every guideline you set up, or how many times you’ve had to reprimand them for doing something they already know is wrong.
It makes much more of an impact to watch dad be responsible, honest, and hardworking than to hear him talk about it. If they see you do it, they are much more apt to follow. Now, I’m not saying don’t ever talk about it, because it is necessary to explain what and why, but leave the “soapbox” under the bed.
Children are much better at imitating something that they have seen than obeying a rule or spoken command. Not to mention that when you pontificate (lecture… preach… elaborate) on a regular basis, even with a righteous subject matter, your child(ren) will grow dangerously tired of it, and you will begin the descent toward exasperating them all the quicker.
Personally, I tend to remind them how often they do, whatever it is that I am reprimanding them for at the time. This is completely contrary to the idea of love being “patient and kind, not being arrogant or rude, and keeping no record of wrongs.” I can say, that I have recognized that the more you can be an example of not holding a grudge, the better your child(ren) will have a chance to escape the gripping sin of unforgiveness.
Above all, and I’ve said it before (and will probably say it again) when you fail to do what you plan to do, for their sake, let them know that you recognize your mistake and are working to rectify it.