Against the grain, otherwise for me it's like not shaving at all as I shave almost daily. There is so little hair after one day that it makes no difference to shave with the grain.
Due to hair growth on some spots I have to go cross and diagonal, I do that when I do the final touch up, applying some extra gel or foam.
Against everytime. I get the closest shave that way.
It's gotta be perfectly smooth. That requires 'against' the grain, and daily.
A combo of both. I usually go with the grain in hard to reach areas...
I typically go against. If i can feel stubble i try all directions.