From Realism to Abstraction
A good way to experiment with abstraction is to start with a photo with good compositional structure.
Abstract interpretation 1:
Abstract interpretation 2. In this version you are responding to Interpretation 1, not to the original reference photos.
From here you can continue making as many interpretations as you want.
From Realism to Abstraction, artist Frank Auerbach
Responding to the movement of line in the painting above. Auerbach drew several variations that lead to an abstract painting:
With each new drawing the artist is responding to the previous drawing, not the original reference photo.
Once the artist was satisfied with his linear composition, he applied colors:
Again, the original reference photo: