Altering postcards is usually about painting and sanding the postcard, then adding artwork over it.
For me it's more about adding to the postcard than altering it, and telling a very brief "story". I truly enjoy doing this. This is the story of the antelope that wanted to fly...to do so, it also needed better eyesight to avoid accidents (since there is no Control Tower for flying creatures)...
And -- because I can't help myself: a collaged painting, Running towards her destiny...?
Be good to your friends -- Kevin Bacon.