Shadow/light:

4 step exercise:

1)Draw the underdrawing with a light pastel or marker. Include feet, draw the weight leg first and use negative space (s).

2) Add shadows, using a dark pastel, seeing shadow as a shape.

3) Adding highlights, with a bright pastel (eg. yellow)

4) Render the figure with Prisma pencil, terra cotta for hair/skin, and black for the swimsuit.

Drawing a shoe from the back or 3/4 back: Draw the heal first and pay attention to the floor line and negative space between heal touching the floor and toe area touching the floor.

Hands and feet can always be drawn starting with the silhouette, seen as a shape.

Draw the figure the "regular" way:

Underdarwing (pastel), adding shadow/light (pastel or prisma), render and refine (prisma).