We discuss working with precision and what exactly using the CCSS mathematical practices looks like. We use student work as examples for visually showing strategies and explaining their thinking.
To help eliminate this problem of "What is good work?" while problem solving, we have a bulletin board highlighting "good work".
Having the arrows with the specific mathematical practice or strategy written on them and pointing to student work has been extremely helpful. I love seeing my kids reference the bulletin board and there has been a definite improvement in the precision and thoroughness of their problem solving work! Yay!
Next I'm putting up a writing bulletin board of student samples, highlighting specific writing techniques and strategies. Keep posted!