How do you minimize power supply noise effects on instrumentation?

Power supply noise mitigation: use linear regulators for sensitive analog circuits (lower noise than switching), add LC filtering after switching regulators, separate analog and digital power planes, use low-noise voltage references, implement proper decoupling (bulk capacitors for low frequency, ceramic for high frequency, placed close to ICs), use differential signaling where possible, and maintain good power supply rejection ratio (PSRR) in amplifier design. Grounding: separate analog and digital grounds, join at single point near power supply. Measure power supply noise with oscilloscope to verify effectiveness.