Use an even, diffuse (soft) light source. A fluorescent lighting and cloudy days provides soft light, as the shadows cast by these sources are usually soft not sharp.
Avoid mixing colour temperatures (warm and cool or incandescent and fluorescent) lighting sources. Different colour temperatures confuse your webcam and make participants look orange or blue
Use a solid blue or green background. Warm colours like pink and orange tend to conflict with skin tones, making participants appear ghostly inside the studio.