Pilots call it a cockpit check. Make it an automatic drill before "takeoff." 

• Seat position
• Mirrors
• Windows-clear
• Brake lights
• Turn signals
• Headlights (low beam please)
• Seat belts
• Fuel
• Horn
• Let's go! DRIVESAFE!

...and for long trips: 

• Oil and fluid levels
• Tires properly inflated (including the spare)
• Wiper blades and gauges
• Emergency kit and flares
• Weather and road conditions
• Essential medical documents on board