This instructors' resource blog post, from 2018, gives concrete and specific examples of using a rubric to give objective and actionable feedback to a student about a piece of writing.  Since rubrics work similarly no matter what type of learning  is being assessed, this resource may also prove helpful to individuals using the rubrics in this collection.  Instructors who use rubrics may also benefit by watching, and sharing with their students, this video on how, as a student, to use the rubric provided by the instructor to get a better grade!