There are two ways to address the problem of judicial activism. One is to ensure that only attorneys who respect the rule of law and the limited role of judges within the separation of powers end up on the bench. This is not always politically tenable: special interests can affect the appointment or election of judges; the organized bar is not always favorably inclined against judicial supremacy; and the perceived value of judicial independence has de facto eradicated the Founders' preferred check on out-of-control judges, impeachment.
The other is for the legislature to more explicitly cabin the discretion of judges. For example, as an initial principle, judges should not be creating implied rights of action, but it sure doesn't hurt to have a "and-we-really-mean-it" law like that the state of Georgia just passed into law to emphasize how lawless it would be for judges to do so. The "lawsuit transparency" litigation, passed with large bipartisan majorities, expressly forbids "implied" causes of action by requiring any private cause of action to be stated explicitly within legislation. It's the first of its kind in the nation. [ALEC; Business Insurance; ILR]