Wash the item with warm, soapy water or a trisodium phosphate solution. Rinse and allow to dry. If the existing surface is sound, all you need do is sand the surface lightly to provide a key for the new paint. However, if the finish is cracked or peeling, you will have to remove it with a chemical stripper or hand sander. You will need to seal oiled wood before painting.
Select a primer according to the furniture and your climate. Oil-based paint is generally more durable but cracks in hot, dry conditions. Latex paints are improving in durability but are difficult to remove should you ever wish to repaint in the future. Metal garden furniture requires a metal primer. Apply two coats of primer, then sand lightly with fine-grade sandpaper.
Outdoor tables look great with a faux marble finish. Oil-based paints work best. You will need white primer; a main color, such as gray, beige or green; a small amount of black; mineral spirits; a sponge and a few large feathers. After priming, apply one coat of the main color and while it is wet, start working into it with the feather to add black veins. You can also create white veins by lifting off the color with a feather dipped in mineral spirit. Use the sponge to cloud the surface slightly. Seal with a minimum of two coats of polyurethane varnish.
Paint each surface of your furniture in a bright color to give your patio a cheery look on even the dullest day. This is a good way to use up leftover paint. Turn chairs upside down to make it easier to reach difficult areas. Seal latex paint with varnish to increase its durability.
Paint furniture in large patches of black and white for a fashionable cow hide effect. Alternatively, paint on zebra stripes. Accessorize with black and white cushions and a matching umbrella for the "wow factor." Or choose two clashing colors for a dash of flair -- bubblegum pink with lime green or deep orange with royal blue.
Use a combination of colors to create a well-used, shabby chic look. Apply the first color and allow to dry. Rub a white candle randomly over the surface, paying particular attention to places where natural wear would occur. Paint the second coat and once dry, use steel wool to expose the first color. Alternatively, use a crackle-glaze kit to achieve an antique effect. These finishes are fragile, so seal with the appropriate varnish for maximum protection.