what will be the starting point for it..?
To Find tooling direction for a part, if nothing data about tooling is available. we always have clues from b side features i.e. mounting features. (there are many ways to find, we cannot say any starting point. Its a trial and error method and depends on our intuition)
One way might be, take a line normal to surface on the top side of mounting feature. and check weather all sides are clearing or not (you should see all sides from this view of line). If it is a good design we almost got it. Still if not, take another line and give angle(1,2,go on till you see all the faces) with respect to 1st line.
If it’s only a styling data without any b side features on it, then it is really trial and error way.
You know even few things about this cannot satisfy verbally. :)
use draft analysis to find the drafts and tooling direction would be perpendicular to neutral element of the draft from cavity.