Find and clean up a studio space with controlled lighting and smooth walls. Hang your blue screen so it drapes down the wall and to the floor. Make sure there are no seams or disruptions in the screen. Make sure the screen is clean and free of any blemishes. Make sure the screen is taut and not loose.
Clothe your actors or subjects in costumes that will not blend into the background. Only dress them in blue clothing if you want parts or things to disappear in the final shot.
Shoot your video or photos in the highest resolution you can. Keep in mind the final image you wish to archive and light your subjects accordingly. If the final image is supposed to take place at night, high noon or day break, light your subject appropriately.
Load your video or images onto your computer and start up your software. For video, software like Final Cut Pro is standard, where for photos, Photoshop is standard.
Edit your photos in Photoshop by unlocking the background layer. This can be done by double-clicking the layer in the layer window. Place the background that will replace the blue screen on a new layer under the blue screen layer. Using the "magic wand" tool from the tool plate, select all of the blue screen. Select the layer from the layer window with the blue screen and click on the "create mask" button, found in the same window. The blue screen will disappear, leaving everything else on that layer. Make color adjustments and tweak the image as needed.
Edit your video footage in Final Cut Pro using the chroma key filter. Load your blue screen shots on "video 1" and the new background images on "video 2." Highlight and double-click the blue screen clip. This will load into the viewer. Select "Color smoothing" and set smoothing to 4:1:1. This can be found under the menu bar under "Effect" > "Filters" > "Key." Under the same menu, select the "Chroma Keyer." Use the eye dropper to select the blue screen as a color sample. This will remove this color from the video. Using the tools, adjust the clip until all the blue from the blue screen is completely removed. Now test the video. The subject or actor in the video should move in sequence with the new background video as if the video were shot on location.