RichyRich
Fellow PA28 amateur here.
If you're losing the line it's probably because, having got it right once, the relative cross-wind changes as you descend. I find that you have to concentrate really, really hard every second - until you get used to it.
I think of it as ....
Ailerons to put the nose of the aircraft on the runway centreline and keep it there.
Rudder to twist the fuselage so it is aligned with the runway.
But for every second you delay as it starts to get away from you it takes longer to get sorted out again.
15kts crosswind at 90 degs when visiting a short grass field last month, and no dragging a wingtip. But my "first time" pax was a little unnerved.
Now I believe that the PA28, unlike the Cessna, actually turns the nosewheel in the air as you use the rudder. So after mainwheel touchdown centre the rudder, as otherwise you start heading off the runway on getting the nosewheel down.