Know When to Celebrate
Drive and a desire for excellence are good things in the planning stages. Strive to make something great. Work as hard as you can, but once you've delivered your best product, be proud of the outcome.
It may not be perfect, and reviewing what needs to be improved is necessary, but don't squelch the moment of accomplishment. Celebrate the effort and time spent, give your team the recognition due, then move on to the next.