One teaching method I used in the western part of the USA was to have the Student fly along a barbed wire fence....as out west those section lines can go for hundreds of miles and if one flies the north/south lines....you always had a cross wind.
Then when they returned to the airfield....lining up and maintaining a track along the runway was a piece of cake to them.
That worked for crabbing or slipping (wing low) methods.....and going back and forth between the two.