I use rubrics to grade written work. I go over the rubrics with the students so that they know how to use them to self score, and I post them in google classroom so they are always accessible. I provide written feedback via google classroom, but grade students in Illuminate.
I do not give zeros. If a student does not complete an assignment, he or she will get a 50%. This means that if you are looking in Illuminate, and you see that your student has only received half credit, the student did not complete the assignment. If the student has no grade at all, it means that he or she wasn't responsible for completing it, or was given extra time to complete it. A "no grade" does not bring the student's grade point average down. A 50% does.
Students are encouraged to redo and resubmit work for a higher score if they would like. They should use the feedback I've given to help them improve. Students do need to email me to let me know they have redone and resubmitted an assignment.