How do I maximize the resale value of my MacBook Air?

Regarding the MacBook Air: Clean it, factory reset it, and keep the original box. A dirty laptop signals abuse; a factory reset proves care; the box shows you’re a careful owner. Together they add $50–100 to a private sale. Wipe the screen and keyboard with a microfiber cloth, use compressed air for ports, then go to System Settings > General > Transfer or Reset > Erase All Content and Settings. Double-check that Bluetooth devices are unpaired and the Mac no longer appears in your iCloud device list.