What should I do if my MacBook Air screen flickers after waking from sleep?

Reset the NVRAM and SMC first. On Intel MacBook Airs, hold Option+Command+P+R at startup. On Apple Silicon, just restart or reset the SMC by shutting down and plugging in the power. Also turn off “Automatically adjust brightness” in System Settings > Displays. If that fails, test in Safe Mode — if flicker stops, it’s a third-party app or corrupted preference file, not hardware.