The direction of the digging equipment helps a viewer understand the scene. Use it to choose the location of the work face, not simply the color of the next machine you buy.
Begin with the contact point
Front-shovel subject
Compose the bank or material in front of the opening shovel, keeping its two-part shape visible.
Backhoe subject
Leave a visible relationship between the rear digging arm and the excavation beside or behind the vehicle.
The 6060 coal shovel and 420F2 backhoe are illustrative subjects, but they are different scales. Their photographs do not form a same-size comparison or establish which would fit the same space.
Make a flat arrangement first
Place the model on plain paper and mark the intended working point. Look from the normal viewing position. If the arm hides the point of contact, rotate the whole composition before committing to raised scenery. Leave the contact point as a visual suggestion; do not make the miniature dig or support material.