Use 'head off' when talking about the beginning of a trip or movement.

Starting Journeys

'Head off' is casual, suitable for everyday conversation, not formal events.

Informal Contexts

The phrase often implies moving in a specific direction or towards a destination.

'Head off' refers to taking action before a problem arises.

Emphasizes the urgency of stopping something negative from occurring.

It can mean interrupting a process to avoid an unwanted outcome.