Empty all the prisons. Every felony is punished by public execution. Immediately upon conviction - no appeal. Every misdemeanor is punished by whipping. Immediately. Use the cash savings to increase the number of law enforcement personnel. Train and arm them like regular army. Nothing promotes a compliant populace like dozens of heavily armed personnel on every intersection! I saw that in eastern Europe in the mid 60's. People there were polite and docile.
G20, G27, G29: One of these is on my person, somewhere.