I always think of shade as being full of light. That is why I like to use the word shade rather than light and shadow. Shade seems to play over the thing, envelop it, better define it, while shadow seems to fall on the thing and stain the surface with darks.

Think of drawing as a way of talking about the things that interest you. Think of those wonderful documents, drawings made on scraps of paper by the lesser Dutch masters while they were wandering around market places and sitting in saloons.

Nature is what you see plus what you think about it.

Don't think of sea as color. Make it a solid that can support a boat. Think of 'wetness' as color-texture.

Always think of drawing, getting the forms realized, emphasizing the design.