“I know a good one when I see it.”

These words haunted my experience as an undergraduate student.  No doubt my professors intended to reassure me that they had some reasonable expectations of my work product, but they failed to enlighten me what those expectations might actually be. I groped around in the dark until I would accidently get it right. I was an anxious mess. I vowed to let my students know the secrets of success right from the start. But what is the best and easiest way to do it?