What is the best way to determine if your trailer has started to skid?

The most effective way to determine if your trailer has started to skid is to check your mirrors. This method allows you to visually assess your trailer's position relative to your vehicle and the road. By observing your mirrors, you can detect if the trailer is swaying or drifting sideways, which are clear indicators of a skid. This visual cue is crucial as it provides immediate feedback on the trailer's stability.

While other methods such as assessing brake lights or listening for skid sounds can provide some information, they may not be as reliable in comprehensively assessing a skid situation. Feeling the steering response can sometimes indicate loss of control, but it does not give a clear indication of the trailer's behavior. Thus, monitoring your mirrors is the best approach for promptly identifying skidding.