Learning from Van Gogh's sunflowers

It's a rainy, windy autumn day in East Hampshire - all the more reason to immerse myself in paintings that bring back memories of summer.
At the immersive Van Gogh exhibition I already wrote about last week, there were several prints of Van Gogh's sunflower paintings.
I personally have found his most famous sunflower painting a little too alive and creepy, but I discovered that he painted sunflowers in many different ways. I particularly liked his study of sunflower heads.

Here are some further lessons that I have learned from Van Gogh
A still life can have many layers: Van Gogh often illustrated all the stages of a sunflower’s life cycle in his sunflower bouquets, creating a metaphor for the life cycle.
Don't shy away from repetition: Just like some other painters I admire (Cezanne, Monet, O'Keefe), Van Gogh painted the same subject over and over again. He got to know sunflowers so intimately that he could write: "The sunflower is mine, in a way.“
Pay attention to the subtle nuances of colours: Van Gogh clearly had an eye for colours, and especially for yellow - he used more than 30 different yellow shades in one of his sunflower paintings...
Use nature as a launching pad: Van Gogh did not try to copy nature, but changed details to suit his purposes.