Head for and head to can be interchanged. 'head for that tree over there" = go to/towards that tree a specific tree "head for London" = go to/towards London "head to London" = go to/towards London To head in the right direction = to go in the right direction. For example catch the correction train on the right platform to be headed in the right direction. = to be going in the right direction. For example to be walking along the correct side of the street/road to reach your destination. London ----->Paris: head for Paris:head towards Paris: head in the right direction for Paris: To be headed in the right direction for Paris. London ----->Paris: head for Paris:head towards Paris: head in the WRONG direction for LONDON: To be headed in the WRONG direction for LONDON. You can say "I'm heading home/back/East/West/North/South/that way/this way/over there/out etc" But not "I'm heading London etc" it has to be "I'm heading to/towards London"

In general and very simplified: 1. head for a destination - go in that general direction 2. head to a destination - go to that destination specifically 3. to be headed towards a destination - to be in the process of travelling to that destination