Vacuum your wicker furniture with your vacuum's brush attachment to get dust and dirt out of cracks and areas that are hard to clean. Wipe the furniture with a damp cloth, and then dry with a towel. Let dry thoroughly. Cleaning helps the furniture last longer.
Place drop cloths on the area where you plan to apply the paint and varnish to the wicker furniture. Put the wicker furniture on top of the drop cloths to protect the ground, floor, or patio from paint spills. Paint the furniture with a paint designed for wicker. This type of paint comes in a wide variety of colors. It will adhere well to the wicker and will help preserve it. Do this every 2 to 3 years.
Apply 2 coats of marine varnish to the wicker furniture with a clean paintbrush, letting dry thoroughly after each coat. This varnish is designed to stand up to rain and many weather conditions. Do this every 2 to 3 years.