Green/ Blue Screen:

You can purchase a ready made screen. No matter which color you are using, Green or Blue, care has to be taken that the screen is uniform in color and shade. You can also make an inexpensive screen by using a table cloth or even a wall that is evenly painted and lit. Spend some time to remove dirt, discolorations, folds and wrinkles. Uneven colors in the screen will result in a video with floating objects and blotches.

One cannot conclusively say that the blue color is better than the green color or vice versa. The choice mainly depends upon the subject (the person or object in the foreground video). It is important that the subject contains as little of the screen color as possible whether in their clothing or as part of an object. For example, if the person has blue eyes, choose a green screen. Another handy hint while deciding the color is analyzing the color scheme of the video which will be inserted as the background. For example, if the background you are going to insert contains images of the sea, then use a blue screen. If the background contains an image of a park or trees, use a green screen. This way you can hide and minimize the impact of the edges that appear due to non uniform or unevenly lit screens.

Proper lighting:

Once you have decided on the color of the screen, the next step is to shoot the subject standing in front of it. If you are aiming for perfection, make sure that the subject has a well defined outline. There should not be small parts of the clothing or even hair hanging loose as you want a sharp separation from the background. The camera's focus should be on the subject (and not the background), to prevent a blurry effect. Be sure no one's clothing matches the background color—if you're using a blue screen, and a man is wearing a blue tie, in the final movie it will seem that he has a hole right through his chest!

The lighting of your background is very important. It should be evenly lit. If it is too brightly lit, then some light will reflect off the background producing visible circles in the final combined movie. Also, make sure that the subject is not too close to the background screen. This is to avoid shadows, which disturb the uniform color of the background.