It is important to do our best in that we put our minds and hands to as well as how we choose to live our life. Choosing to do our best, is our way of living a life of excellence (not perfection). Three ways that you can you live a life of excellence are:
Keep your word as best as you and do what you tell people you are going to do.
Finish what you start, even if it takes you longer than anticipated.
Always be honest and truthful with yourself and others.