Some quick tips that I offer to my students in regard to creating further distance in their landscape paintings are as follows:
*Look for the ellipses in the landscape and translate them upon the canvas. The ellipses help to create movement and draws the viewers' eye through the picture.
*Be aware of scale and perspective. Contrast and compare the shape and scale of the objects. Things get smaller as they recede into the distance. Think about how much of the sky will appear in the picture. By merely raising or lowering the horizon line, one can shift the perspective creating more or less depth within the painting.
*Be cognizant of any kind of repetition that maybe occurring within the painting. We may sometimes be unaware of the consistent repetitive shapes or equally spaced out items we are creating. Shapes and spacing are quite varied in nature and are not as systematic as we sometimes unconsciously portray them. Constantly observe, compare your work to the landscape and be honest about what you see in your work by comparison to the landscape.
*Determine where the point of focus will be. Consider positioning the highest light a third in and a third up on the canvas.
TO PUSH THE DISTANCE:
*Reserve the foreground for the darkest accent. By having a dark in the immediate foreground it will help to push the distance in the picture. A dark accent in the middle or far picture plane will instantly collapse the illusion of depth.
*Sunlight values remain consistent through out the picture however as sunlight objects recede into the distance they lose their local color.
*Shadow values vary. Shadows in the immediate foreground are darker and generally have more local color. As shadows recede into the distance they get lighter and bluer (blue-gray or blue violet.)
*Be mindful of the illuminating source, the sky. The sky may exhibit variations in color and is not always one solid color of blue. Skies are prone to having atmosphere therefore should be examined for subtle differences of the spectrum. The sky nearest to the sun will be brightest and perhaps lightest. The atmospheric sky furthest away in the distance may have subtle variations and may appear less blue. Look to see if you can see the spectrum and indicate as such. Always examine that sky!
*Pushing the distance in the sky is also about the clouds. Sunlight clouds in the furthest picture plane may appear to have a touch of red in their "white tops" and their shadow bottoms may appear at times to blend into the background sky.
*Emphasis of texture generally is placed upon the objects in the foreground while texture generally becomes more subtle and less noticeable in objects in the distance.
*Treatment of edges and line. The more solid the edges and lines appear, the more the objects appear closer. The softer edges and lines appear, the more the objects appear to recede.
*Lastly, never give up. Be indefatigable. Landscape painting is humbling and unquestionably it presents its challenges. It is not always easy to paint and perhaps it is not meant to be easy. It is the struggle that makes us better painters. In time with much practice and direct observation from nature, one shall improve and ultimately triumph.