I do not always do several sketches for a painting, but I usually do at least one. For this composition I needed to rearrange a few items and analyze the changes in shading. It helps me to look at one concept at a time: imagining spheres under the curving fronds and stems, exaggerating contrasts to see edges, tracing out where light hits and is blocked, areas of color and white to preserve. Also, I am changing the format from a square image to a portrait, enlarging, and possibly leaving room for a text overlay. To do that, I had to study the structure of the blossoms to understand the relationships better.
Strangely, I do not look at the sketches when I am actually painting. After the studies I understand my plan, and I can adapt as I go along. With options available I can accept the way the watercolors react to the paper more gracefully.
Wish me luck.