Geometrical shapes or patterns can be used as a stimulus during meditation.
The Circle
The circle has symbolic meanings and thus provides an ideal focus for meditation. Symbols such as circle hold a power in and of themselves. When you are meditating on a circle use a white background and draw it boldly in black, with a dot in the center. The circle should be 1 foot in diameter.
Place it at an eye level on the wall when you are meditating. Focus on your breathing for a moment. Blink whenever you feel uncomfortable (but keep the blinks to a minimum).
After regular practice you will notice that the circle is having its own effect on your life. It may give you insights into yourself that you thought was impossible, influence your dream life or take you towards greater tranquility in your daily affairs.
Others
In similar fashion the cross that is a symbolic shape of many religions also can be used for meditation. You can mix and match different geometrical shapes like the circle, triangle and squares to create your own shape that has some direct special meaning to you. You will achieve the meaning once you start feeling harmonious, balanced and will experience a feeling that simply pleases you. Don’t stop there proceed further.
Using Inner Vision
Each of us has the ability to visualize. Everyone dreams and everyone can be taught to recall the dreams in the morning (with a little bit of training). Due to our simplified, well-equipped modern life we have lost our ability to recall visual images.
Develop your powers of visualization by gazing at any geometric shape and then memorize it. Then close your eyes and hold the shape in your mind as long as you can, but without any effort. When the image fades, open your eyes and gaze at it once more. And when you are ready close your eyes and repeat the exercise once more.
After practicing several times you will able to visualize the shape even without first gazing at it. Repeat the exercise with several other shapes and once you have mastered, play around with these shapes in your mind by combining and separating them. In later stages you can even associate colors to the shapes.