The main trick with avoiding neck pain is to reduce the angle between your neck and back. Yeah, sure, everyone knows that. But the trick there is to flatten your back, especially your upper back. If you look back through the above photos, you'll notice quite a bit of variation in upper back curvature and you can easily see how a flatter upper back will reduce neck bend. There's an old thread all about this, here: Riding Position Discovery

It works. Of course neck exercises also help. When I go to the gym in the fall, I start with a bunch of upper upper body strengthening work, shrugs, dumbbell presses, side and front raises, that sort of thing. I think that helps some. A RAAM rider who succumbed to Schermer's Neck on year came back the next having strengthened his neck, no problems. He also used a head harness from which he suspended a plate and worked his neck that way. You can find them online.