Artstation - Concept Art for Games - First steps with Matt Kohr

https://www.artstation.com/learning/courses/0OZ/concept-art-for-games-first-steps/chapters/G7Z/one-part-relates-to-the-whole

This course introduces the fundamentals of concept art for games. Focusing on the functional roles that objects play, the course takes an ‘inside-out’ approach to design thinking.  Learn to critically investigate forms beyond surface-level shapes. With an emphasis on logic and problem-solving, no pre-existing drawing skills are required for this course.