Betty Edwards' book "Drawing on the Right Side of the Brain" is great for this. https://www.amazon.com/Drawing-Right-Side-Brain-Definitive/dp/1585429201/ https

Betty Edwards' book "Drawing on the Right Side of the Brain" is great for this. https://www.amazon.com/Drawing-Right-Side-Brain-Definitive/dp/1585429201/ https://www.amazon.com/Drawing-Right-Side-Brain-Definitive/d... https://www.drawright.com/ https://www.drawright.com/