GREEN OR BLUE?
Both work fine, if you are going to be using green objects as props, use a blue screen and vice versa. Make sure the cloth is stretched taut without any wrinkles.
LIGHTING THE BACKGROUND:
Your goal for lighting the green screen is to keep it as evenly lit and uniform as possible. Use four main lights to evenly expose the chroma background. If you are getting hotsopts, try using bounce. Flag any light leaks.
LIGHTING THE SUBJECT:
Use a rim light behind the characters head to easily separate him from the backdrop. A fill light in front of the character, 45 degrees on right or left side. Soft lights or chinese lanterns work well as a fill light. Your fill lights should not fall on the background. If you have the photo you are using for the background, study the lighting in the photo and try to match it. If the sunlight is coming from the right side, light the subject from the right.
The character should not stand too close to the chroma screen as this will cause a shadow on the screen. Distance between subject and camera should be at least 6 feet.
Do not use linen clothes. The light goes through the cloth and makes it transparent.
Do not use cloth material of thin stripes or small checks or patterns as this may jitter.
It is obvious that you should not wear green clothes, or any shade of green.
Do not use white, it tends to get blown out. Darker shades are preferable.
Always carry backup outfits in case one is not working out.
It is difficult to remove chroma from curly/frizzy hair. Make sure your characters hair is gelled to prevent difficulty in post.
If the character is wearing glasses, remove the glass lenses from the frames. Keep empty frames.
Make sure all accessories are matt, not glossy. Glossy surfaces have white highlights, which pick up the green colour around it. This gets erased during post when you remove the chroma background. For example, if the character is wearing glasses with glossy black frames, the white highlights will reflect the green. Or if a woman is wearing shiny silver bangles., change them to matt material.
Write down your settings! In case you have to come back and redo a few shots.
A fail safe method is to actually shot a few minutes of footage, give it to the editor to remove the chroma and see if he has any difficulty, or if you need to make any changes to your lighting.