Establish what quality looks like.
Students should be always be asked how they can improve any work that has been assessed as low quality.
Teachers should not accepted improved work until both the student and the teacher agree that it is of substantially better quality. When there is a difference between student and the teacher's assessment of quality the difference should be discussed. From these discussions, or 'learning conversations' students learn to judge the criteria of what determines quality in any learning situation.

Start slowly and celebrate small successes.
To start the process, with students not used to the idea of Quality, it would be reasonable to initially accept any work as long as it has been improved in any small way. What is needed at first is to get non-workers started. Students who in the past have not been encouraged to make the shift to quality work will at first grow tired and refuse to extend much effort. Such students will need to be introduced slowly to the idea of quality work and will need encouragement and support. With every small success students will begin to feel the power and personal satisfaction that goes with quality achievement in any area of learning.

Quality is what we do around here!
By developing this quality improvement 'mindset' students will gradually realise that it is their responsibility to continually improve their work. All teachers need to strive towards students eventually setting and living up to their own quality standards. Even students who in the past haven't bothered to work hard will begin to feel good about their work and in turn begin to see school in a positive light. Once quality learning becomes accepted as 'the way thing are done' in the classroom students will feel proud of what they and their classmates can do.