One may not forget to think of the sum J=L+S as a vector sum, so when you do this you get the following results: When J=2, L and S are parallel and point in the same direction, because when adding 2 vectors of length one results in a vector of length 2, this must be the case. When J=1, L and S are perpendicular to each other and when J=0, both vectors must be antiparallel (parallel and pointing in opposite directions) in order to add them up to 0.