I don't know where Ivan.t.H learn't his nav but most of his advice seems to me to be how NOT to navigate. You should NOT be sweating buckets after a navex, if he is picking checkpoints every 2-3NM though I can understand why he IS working so hard!
One thing I would agree with though is to forget the 1:60 rule, for most people it is far to difficult at PPL level and drawing 5&10 degree drift lines is a much easier way of estimating track error (you only need to draw them ONE side of track, if you go off the other side you can still see the error by looking and it does not clutter the map as much).