Download the Channels B&W Conversion Action.
Instructions for installing actions in Photoshop Elements are here.
Using the Channels B&W action:
- When the action finishes running, the image will still be in color.
- Turn on the eyeballs, one by one, to see what each of the color channel layers looks like individually.
- Decide which channel you like best for each part of your image.
- Mask accordingly. Paint in black on each layer mask over areas that are more appealing on another channel layer. Leave white if this is the channel whose B&W version looks best to you.
- This Layer Mask tip will help.
- Remember that you can adjust layer opacity as well as brush opacity.
- This screenshot of the layers palette from the above picture shows like the red layer looked best for the greenery in the background, the green brought out the detail in the wall and dark colored boxes the best, and the blue channel converted the light colored boxes the best.
- I used the dodge/burn layer to tone down the reflection of the sun on the hinges and tops of the boxes.