Sketching with a Copic Pen, Renee Jorgensen's freehand work
Select a specimen. I have some crab apple blossoms from the tree in my front yard - probably destined to freeze! But, they're drawable.
Crabapple sprig, #2B Tombow pencil on paper, Libby Kyer
Polychromos pencil on tissue on top of graphite drawing, Libby Kyer
Pull the tissue away from you sketch. You'll still see "shapes" even though there are no outlines. This means, you've got the right tonal values in the right place to create good form.
Form separation, showing using the "wrong color" to explore tonal values needed for form, Polychromos on tissue, Libby Kyer.
You can see that it's hard to confuse form and local color if the color you're using doesn't relate to your specimen. You separate thinking about form into one exercise, and mapping local color when you're planning your palette with another. This works really well for specimens that have local color that is tonally very close to that needed for form. The blossoms in this image in reality are a deep rose hue, with no white anywhere. The leaves are deep green, that is about the same tone exactly as the rose hue.
Give it a try! Don't forget to share your successes with us on the blog!