Imagination Then Sketching Then Painting

  I recently wrote a post about painting from life Vs. painting from photographs.  I've had a sudden inspiration about this, which could help artists.  I was up late last night reading a passage about Bouguereau which I'll paraphrase:  "After imagining the scene for the painting in his mind, he would make a quick oil sketch.  Then, he would draw all the elements from nature.  He would surround himself with these highly detailed drawings to produce the final painting."
  I feel like this is something that artists have lost in the past century.  We don't take the time to draw from nature and then use that drawing to produce a finished painting.  Instead, we (I included) rely on photographs to share some of the load.  My process for a pet portrait was to photograph the animal, then sketch a composition and the dog's face, and then paint from the photographs.  Now, I'm going to paint directly from the sketches and sketch from nature whenever possible.
​  The other part of this is the fact that drawing is necessary to train yourself for painting.  You're not gaining any skill when you take a photograph, but you are gaining massive skill when you do a drawing; this skill is brilliant for painting.
  This also makes sense in regards to color.  Bouguereau's students would say how he created colors which never existed in nature.  I always found this perplexing.  I know he would be influence by his model and color memory, but his color had to be more from his imagination instead of copying color (not to mention that there were no color photos in those days).  He was painting from drawings and oil studies which don't have colors set.  He wasn't influenced by digital colors at all.  The color scheme would come from nature + Bouguereau's imagination because there was no other way.
  I'm going to try this out on a portrait and I'll report back with the results.