Everyone's mileage clearly will vary on this - perhaps the one thing we can agree on with the neck.

Prep is a big deal. I have sensitive skin and I need a nice amount of time with a good lather (I have to sometimes wash away what I've done and start over to get the lather right), re-applied while shaving to make sure everything is nice and moisturized, etc. Of course I'm also softening the skin under hot water in the shower, etc.

I do a N-S pass after shaving the chin. It's more of a continuation of the cheek and chin shaves than really trying to get the hair on the neck, which runs every which way. But if I get a few, great. I am very careful about the angles to try and maximize cutting efficiency.

When I do S-N, I use my right hand on both the left AND right side of my neck. It's pretty darn hard to turn your neck to shave the right side of your neck with your right hand, but that itself creates a slightly different cutting angle that seems to do a lot. I do the same with the left hand.

I also do a bit of scything action in certain areas. Again, sometimes with right hand>right side awkwardness to add in some different angles. I don't spend forever on the neck - this is still a fast shave. But the neck might get a total of...4-5 passes. N-S, S-N from each side, then a bit of scything to finish off.

It's pretty close now.