Are scars a preventative factor?
The real question is where the scar is located and can it be covered up with makeup. Many photographers are also able to Photoshop any unsightly scars. At the end of the day, a scar is not going to make or break a potential modeling career. Many models have scars and are heavily booked.
Do I need to have professional headshots?
Professional headshots are great and a model-to-be should definitely have these on hand. The inside scoop from the modeling agencies however is that they really want to see natural, non-professional photos. Anyone can cake on makeup and have a photographer Photoshop someone until they look absolutely flawless. However this doesn’t mean send in pictures featuring you drinking at Mardi Gras either. Use your regular camera outdoors in natural light, wearing little to no makeup, natural hair and by all means does not make the instinctual mistake of tilting your head ¾ to the camera as everyone looks good at this angle. This means submitted shots straight on, direct side profile and full body as well. Last, if you are submitting via email, do not send files that are so high in resolution that you may crash one’s computer. This typically makes agents cranky and don’t count on them to pull images from a flash drive either.