We started out by viewing a reference photo on the TV. Gabor used PhotoShop to simplify the photo into larger shapes so we could focus on the “big picture” instead of getting bogged down with the details.
As we proceeded he changed the filter to bring out the definition. The last 30 minutes of the 2hr exercise we were looking at the original photo.
This really helped us to block in the big shapes and work on values ahead of the details.