Don't get into the habit of lining up some part of the car with the line! That will keep you staring at the car and the line, instead of looking at the road and the other vehicles.

Look well down the road, and position your car so that you are sitting just to one side of the centre of your lane. This will keep your car centred in the lane. It soon becomes a natural reflex, and because it does not depend on using some part of the car as a marker, you can drive a different vehicle just as well, without having to set up new 'sights'.

It also gets you watching what's happening 'out there' where you need to be paying attention.