How to teach diligence

I have really wondered, at times, how to teach diligence to my children. I have three boys ages 5, 4, 14mos. I would really like to begin teaching them about diligence now, but I get frustrated with myself and what seems like a lack of diligence on my part. I think about what people say concerning raising children--you know the more is caught than taught?? Well if that is true, then all I can see is the fact that I oftentimes do cut corners because I have so many corners to keep clean. I get frustrated with the example I set to my children because I feel like I am not diligent with every task. The problem is, there is no way I could be diligent (perfect) in every task I do. I wouldn't get everything done sufficiently. I would have 50% of the needed work complete and the rest would be completely undone. Do you see my dilemma? So how does a busy mother attempt to teach something that she struggles with herself?? Perhaps I should look up the word diligent, to get a specific definition. 'Cause, you know, perhaps what could make the difference is a phrase like "given certain circumstances". I just hope I can make my children see that I am diligent over the whole host of my sphere, and that what is perceived as cutting corners is for the purpose of getting it all pretty much done, so there aren't any glaring problems in the home.