How do you fix idle speed?

To fix idle speed, first ensure the engine is at operating temperature. Then, locate the idle adjustment screw on the throttle body or carburetor and turn it to increase or decrease the idle speed as needed. Additionally, check for any vacuum leaks, and inspect components like the throttle position sensor and idle air control valve, as they can affect idle performance. If necessary, consult your vehicle's service manual for specific procedures related to your make and model.