Sketching is one of the most helpful skills for an engineer. A good sketch easily conveys a design concept. However, becoming good at sketching requires practice and discipline. These BYU Design Review articles are an excellent way to get started sketching.
Learn to Sketch: Part 1 — The BYU Design Review
Learn to Sketch: Part 2 — The BYU Design Review
Learn to Sketch: Part 3 — The BYU Design Review
Learn to Sketch: Part 4 — The BYU Design Review