These are rain barrels I purchased at Murdoch's ranching supply, and they were an ugly green color, but the plastic is imprinted with woodgrain texture, so I saw potential. I started off with the following colors of MATTE FINISH (that's important) spray paint: Nutmeg, Warm Caramel, Fossil, Espresso & Dark Walnut. Then I also purchased a can of GLOSS FINISH black spray paint and oil rubbed bronze paint as well, in a quart sized can. Anything that's supposed to look like wood should be with a matte finish paint, and the gloss & oil rubbed bronze is used on the metal looking parts. I prefer the 2x coverage rustoleum paint, because it's thick, and it seems to adhere to plastic really well.
Step 1: Take the nutmeg paint and paint the wood grain in that color. You want to hide the green plastic with this step. Don't worry about covering the "metal" parts of the barrel until step 7!
Step 3: Repeat the step above with the fossil colored paint. Be a bit more liberal with your fossil colored stripes - these highlights give the wood a more natural look.
Step 4: Now add stripes in Espresso! Liberal coverage here is very good. And I tended to concentrate it a bit towards the top and bottom .
Step 5: Now it's time to use the dark walnut paint and make it look like wood. Take your time on this step. All the other steps were really just quick coverage. I went back over it a few times, and made sure the stripes of paint from previous steps were visually broken up. This dark walnut color will be the main concentration of color on the barrel, so be generous with your coverage, but allowing those underlying paint colors to peek through.
Step 7: My favorite step! Paint the tops with the black gloss spray paint, and use a smaller brush to add the "metal" ring details with the oil rubbed bronze paint.