These have been a great source of inspiration to me over the years and I hope you find them helpful.
Try planning a picture in ivory black and raw sienna.
When we start a picture we begin with a shape. Our first problem is to introduce into the shape a form. It may be only a line that will tie the sides together.
If the distance is dark the values will grow lighter towards the foreground.
One authentic detail will make the whole picture.
You cannot paint a picture from the model.
Keep repeating your main values it will give your picture unity.
An arm is all one; paint it so with one stroke of the brush
Play up to one color note
Light and dark, warm and cool colors, in equal proportions produce static neutrality, balancing each other right out of the picture.
To simplify your scene, paint as many things as possible in the same value. Then vary the texture and edges. Let modeled form come against flat surfaces, detail against simplicity, hard against soft etc.
When the center of interest is established in its tonal relations, that becomes the key to the picture and you have to stick to it whether you like it or not.
Eliminate everything that is not relevant to the main purpose.
When two values nearly alike come together, paint them as one value.
Dark in light must be at least as the shadow tone of white. If the light is soft paint it soft.
Form is expressed in the light tones by dark accents, in the dark tones by light accents.
Pictorial art is relating tones to create beauty- like chords of music- not the faithful copying of the model.
In the model there is a confusion of tones that have no meaning in art.
Do not have an important dark and important light in the same picture they will destroy each other.
If you see a thing dark make it darker; large paint it larger; small paint it smaller, then your work will be positive.
One dark accent will give accent to a high key picture.
Make your picture either a figure with a background secondary or a landscape with a figure secondary.
One dark note in a passage of light will heighten the effect of light.
To make light more brilliant, raise the value of the shadow. The light in your picture must be kept separate from the shadow. If you bear in mind that the light on dark must be at least as light as the shadow tone of white, your values will take care of themselves.
Begin a picture by first laying in the values, and then clearly define the edges.
Paint the large areas as indefinitely as you like, but paint the details with integrity.
