Bribery is a common one, counterintelligence is another, compromising people who are investigating them (or their family members)

Along with radicaldreamer suggestions it's also common to be really effective at stonewalling police while on secure wire cameras with audio recording and to have very good criminal lawyers on retainer. Also having patches and wannabes who are prepared to scapegoat themselves.

This isn't so much directly evading law enforcement but it's effective as it can easily cause police take actions that cause evidence and cases to be thrown out, raise reasonable doubt, etc.

Depleting resources and diversions are also relatively common, creating a 'fake' public threat or hate crime to investigate bleeds police resources away from ongoing investigations, etc.

The tango between gang squads and organized criminal groups is an ongoing escalating battle. The EncroPhone transcripts revealed a lot.