How to quickly determine general vibration location

Gather any important information regarding the vibration (ie speed, temperature ect)

Go for a test drive in the vehicle that is presenting with a vibration (if it is safe to do so)

If the vibration is in the steering wheel, check the front axle and tires

If the vibration is in the seat, check the rear end and tires, or driveline if a rwd/awd

If the vibration is worse under acceleration/deceleration check the powertrain

This may not lead to the exact problem, but will start you on the right foot