Sketching is likely THE most valuable exercise you can do to improve your drawing skills. Also drawing from life is another. If you sketch daily, you'll soon see your ability to render form and light grow by leaps and bounds.
I will post a list of items that you can choose to draw. The rules are:
1. You MUST draw from life. No photographs!
2. You can choose to draw one item or the whole list.
3. Post your sketches as you do them.
4. The list will last for one week, then be replaced with another.
Remember these are sketches, not finished drawings. Of course you can make them as detailed as you like, but normally sketches are looser, unfinished drawings.
Its that simple!
The List
An egg
A shoe
Your toothbrush
A spoon
Something red
Your favourite chair
A salt shaker
Your breakfast
The view from your living room window
A fallen leaf

