To flash or not to flash?
Many amateur photographers use flash on EVERY photo they take. Just assuming flash makes it better. I was one of them. The truth is, using flash can rob pics of natural color. Especially on skin tones.
While I am aware that most modern digital cameras have made great improvements to keep natural skin tones, there is still no comparison. As a photographer my goal is to preserve the natural colors that I see with my eyes.
As as a rule of thumb I won't use flash unless absolutely necessary. Or unless I'm in a studio setting where high detail and controlled lighting is key. In that setting I am using soft boxes and diffusers over my flash strobes to soften the light.
My point? Shoot with no flash if possible. That will produce the most natural look. Especially when photographing people.