I have been confused about what to tell Unicom/Tower after requesting/announcing departure… What direction to enter (Ex.: departing south)… is it south with respect to the runway or to the map?
It’s more with respect to the airport based off of the flight plan you should have created. You could be taking off from a runway that faces north but you would announce “departing to the south”.
Explaining further to @DeerCrusher correct explanation, and adding logic to it; when you announce takeoff, you announce the runway you are taking off from, hence the initial direction is already known. The ‘direction’ you are giving is where you intend to fly to leave the towers airspace.