I think the biggest problem is that since we are sitting so close to the cg we (and especially as new student) really don't feel yaw that well. So I try to teach seeing it. On the first lesson, after explaining adverse aileron yaw, I'll demonstrate a rudderless turn and one with rudder, asking the new student to watch the nose of the airplane.
They can usually detect that movement, so learning coordination becomes (at least I try to make it) part of the basics of visual flying. (I think it helps that I like to cover the isnstruments to force the view outside)