Arrange a still life with basic shapes. Keep it simple to start with. Use blocks, cans, bottles and balls. Objects should not be shiny and should be of one color. Paint bottles and cans with matte house paint to achieve this end.
Direct a strong light on the still life. You will probably need more than one light in the room to see what you are doing, but the still life objects should be illuminated primarily by one light source. Traditionally, the light source would be above and to the right of the subject.
Limit your pallet to black and white, or replace the black with a dark, earth pigment such as burnt umber. Mix a mid-tone gray or brown by combining white with your dark color. Prime your canvas with this mixture and allow it to dry before you start to paint.
Outline the basic shapes of your still life with a thin dark line. Mix a shade to match the darkness of the objects' shadow sides and block in dark areas. Let the primed canvas show through for the mid-tones and mix in lots of white for the highlights. Paint the shadows that the objects cast on the table.
Go back and adjust the values to make them consistent throughout the painting. Pay attention to the differences in value and to the transitions from dark to light. Unify each object by refining the relationships between dark and light areas. Notice how this rounds out the objects by giving them a sense of dimension.
Add color after the monochromatic under-painting dries. Gradually build up color with transparent glazes, allowing each layer to dry before adding the next, or apply the paint opaquely using the under-painting as a guide.
Advance to more complex subject matter after you have gained some understanding of how the light source illuminates simple shapes. Practice with shoes, gloves, fruit and eventually move on to portraiture. See the face as a combination of basic shapes and paint their areas of light and shadow as you have learned to do with the simple still life.