Here’s a step by step lesson on painting a bunch of grapes from a reference photo.
First, make sure you photograph your subject in bright, dramatic lighting. Long shadows and transparent grapes are exciting to paint.
To see a couple of videos of me painting the shadow shapes under the grapes click on this link https://photos.app.goo.gl/Ga99qyJJAJDjFUgN8
As I continue to work with oil paints I find that using large brushes and a small canvas forces me to be more impressionistic which is what I am striving for.
Many years ago I took photos of the lily pads at our local Sequim pond. I have tried painting this scene several times over the years and just could not create the painting I wanted. Finally I realized I needed to take a smaller bite and crop the reference image until it had just a few major dark and light shapes. I cut 1/4" foam core and 400 grit UART paper to the size of an existing frame. I mounted the UART sanded paper to the board, drew in the rough lily shapes with charcoal and then slathered on dark neutralized watercolors.
Another example of pastel over watercolor; a pencil sketch on 300# Arches watercolor paper.