Sketches: When starting on still-life images for a client I always make hand-drawn sketches.
These sketches are an indication on the direction the final image will have. When everyone has agreed on the sketch I start gathering material for each image. The plants and fruits (for ex.) I end up with decides how I build the setup. Are the plant bending left or right, how is the pear shaped, what colour grading does the peach have etc.