1) End all 'three strike' laws and prevent anything similar from ever being used in the future.
2) End compulsory sentencing.
3) End the monopoly on bar associations to practice law or be judges.
4) End prison labor, except for on complex labor (repairing the building, farming etc...).
5) Provide services to the inmates to actually help rehabilitate them.
6) Provide services to make it easier for them to actually be reintegrated into society. As it is if you are charged with a felony your life is over and you have no choice but to commit crime to survive.