Justices practice judicial restraint when they

Make rulings that change the laws passed by congress.

Justices practice judicial restraint when they make narrow decisions that only relate to a specific case.

Explanation:

Judicial restraint is a principle of separation of powers that must be taken into account in judicial decision-making.

According to this principle, the case law should not answer or anticipate questions that fall within the original area of legislative or executive power (legal activism). These should not be answered and made binding by the highest courts, but rather by the constitutionally provided and legitimized bodies such as Congress or the federal government.