Familiarize yourself with the basic aesthetics of modern mid-century design. This mid century modern furniture usually have odd shapes, clean lines and vivid colors, and is often made of unique building materials. You will need to be taught to identify those qualities that you can start seriously shopping.
Famous modern designers of mid century modern furniture is Arne Jacobsen, Harry Bertoia, Eero Saarinen and are some of the most famous designers during this period of time, and you want to be able to identify their own work or work with their influence.
Keep an eye on classified ads for furniture, both online and in print. You can often find a great piece of mid century modern furniture design that is being thrown away by someone who either does not know or care about what is actually worth. Teach yourself to spot the differences between a genuine piece and a reproduction. Upholstery, frame materials and build quality that can all clue to the true origin of a particular piece of furniture.