Clean it, reset it, and keep the box.

Yes. Those three things matter more than any “special” optimization.

A dirty laptop screams “I was abused.” A factory reset proves you actually took care of it. The original box signals a careful owner. Together they add maybe $50–100 to a private sale.

Don’t overthink it. Wipe the screen and keyboard with a microfiber cloth. Use a soft brush or compressed air for the ports. Then go to System Settings > General > Transfer or Reset > Erase All Content and Settings. This signs out of iCloud, disables Find My, and wipes the drive clean. If you’re on an older Intel Mac, boot into Recovery and use Disk Utility to erase the drive before reinstalling macOS.

The one thing people mess up: forgetting to unpair Bluetooth devices and turn off Activation Lock. Double-check that the Mac no longer appears in your iCloud device list.

A clean, factory-reset MacBook Air with its charger, box, and no scratches tells a buyer “this was loved.” That’s the whole secret.

Don’t bother with resale guides that tell you to reinstall a specific macOS version or run benchmark tests. No one cares. They just want a computer that boots clean and doesn’t smell like spilled coffee.