How to Paint Wicker Furniture
Start by vacuuming off the dust, and wipe off loose dirt and cobwebs. To get into the grooves and small crevices, cut off the bristles on an old paintbrush, leaving about 1" of the bristles remaining. The bristles will still be soft, but they'll be stiff enough to help dust the furniture. An air compressor also works well for blowing out dust.
Spray Paint the Chair
Now that the furniture is prepared, begin painting with spray paint or a power sprayer. It's preferable to paint indoors, where no dust or insects will spoil the finish. But paint outdoors if the ventilation isn't adequate inside. Use a good enamel paint suitable for wicker furniture (most paint labels list the surfaces the product is suitable for). Hold the spray can 8" to 10" away from the furniture, and spray back and forth for the most even coverage.