When I was teaching, I found rubrics to be an effective tool. They helped me clarify what I was looking for, both for me and for my students. But they can also be challenging--to write and to use. On the right, you'll find characteristics of effective rubrics, but here let's talk about how I created and used rubrics.
First, I decided on my grading scale, whether it was A-B-C-D-F or Excellent, Good, and Needs Work. This 
depends on your purpose. Next, I wrote the criteria for the top grade. This would be exceptional work that goes above and beyond standard expectations. Then, I wrote the lowest category--what would it look like if a student totally "blew it" on the assignment? Following that, I wrote the middle category, with it falling in between the top and bottom. From there, I wrote any further gradations I might have. Here's a rubric for your rubrics.
Next, I taught my students the criteria, using it as part of the assignment. I wanted them to clearly understand what I was looking for. Then, I showed samples of what "good" would look like. I used samples from the prior year, and showed several examples at the varying levels, guiding students through the process of determining the "grade."
Over time, I shifted to students helping me develop the rubrics. That built ownership, and gave them a clearer perspective of the assignment. It also increased self-direction.
