2: Ignoring Leaks
The job of the fluids is to stay in the vehicle, and cool it, or make it run, or lubricate components etc. This means they are not supposed to be leaking out. Learn the various fluid colours so you have some idea what is leaking, and how severe the issue is.
Coolant: Green or Orange
Transmission Fluid: Red
Brake Fluid and Power steering Fluid: Clear
Oil: Caramel when fresh and Black when used