Set up the blue screen. For painting a wall, make sure the wall is primed white and has no blemishes on it. Paint the wall with the chroma key paint. Make sure it is even without darker or lighter areas. Blemishes and unbalanced paint will cause shadows or "ghosts" in the final edited product. For a material or tarp, make sure they are taut and not flapping for the same reason.
Dress your subject in colors that will not blend with the chroma key (unless you want parts of him to disappear). Since the blue is deep and bright, don't put the subject in a bright T-shirt or use a bright blue prop.
Paint the floor blue or use a silver reflector if the floor needs to be part of the effect. For example, if the subject needs to be floating or walking on water, the floor must be manipulated in editing.
Capture the images needed. Whether it is film or photography, light the subject and capture the image in as high a quality (resolution) as possible. Lighting should be as if the source was in the background footage to remain consistent. So have a good understanding of what the lighting is: outdoor, indoor, day or night.
Upload the images into the digital editing program such as Final Cut for film editing or Adobe Photoshop for photography.
Replace the chroma key in Photoshop by unlocking the original layer and drag the new image over the green screen image. You will now have two layers. Make sure the chroma key layer (green screen image) is layer one. Take a sample of the green to be replaced, then, with the fuzziness scroll tool, move the bar until everything you want to keep is as black as possible and everything to be removed is white. After clicking "OK," the subject should be selected and you can delete the background.
Capture the footage into Final Cut Pro using the chroma keyer filter. Place the green screen footage on Video 1 and the background footage on Video 2 lines. Double-click the clip to be chroma keyed, loading it into the Viewer. Go to Effects>Filters>Key>Color Smoothing 4:1:1. Go to Effect>Filters>Key>Chroma Keyer. Select the color eyedropper, and grab the color to be removed. Continue to clean the section until the blue is completely gone. When Video 1 and Video 2 are played simultaneously, the background should appear with the subject in front.