Study the aesthetics, principles and techniques of Japanese art and furniture design. Focus on the fundamentals of joinery as the Japanese techniques are typically far more complex than those used in most Western traditions. Learn to join two pieces of wood together by various means without using nails or glue.
Learn the proper technique for using Japanese tools, which typically work differently than their western corollaries. Practice using a Japanese saw, for example, making each cut during the pull stroke instead of the push stroke. Use the tools on scrap wood and then on the same type of wood you plan to use for your first furniture project.
Select the type of furniture you wish to build. Opt for a fairly simple structure if you are new to woodworking or if you plan to follow authentic Japanese techniques. Build a shoji screen, for example, for a piece of furniture that doesn't have to support any weight. Build a simple table in the spirit of a "kotatsu," keeping it low to the ground.
Consult with an experienced Japanese woodworker about your design before you begin to build. Stick to a ready-made set of building plans if you do not have access to a teacher experienced in Japanese furniture-making methods.
Follow traditional Japanese aesthetics in selecting hardware or decorative elements for your piece. Keep wood unstained or use a natural stain to enrich its color. Use a Japanese hand plane instead of sandpaper to smooth the wood's surface. Avoid colorful paints. Use natural lacquer to give the surface a degree of sheen.