BIGGER IMAGES ARE DEFINATELY BETTER
Make sure you have as much detail as possible, if it isn't blurry or pixelated you should be all set! avoid using digital zoom, or cropping a small face from a bigger photo.
THINK ABOUT THE LIGHT
Dramatic lighting, particularly coming from one direction can add interesting shadows that make for a much better portrait drawing.
Avoid images where you have used flash as it can flatten the face.
Natural light is best. (there are some lovely shadows on the examples below)
UNPOSED OR DRAMATIC POSE
A natural pose can work really well, or the reverse and displaying genuine human emotion! be brave and laugh, pull a face and experiment, this can lead to really exciting art.
Make sure you don't use any filters on your photographs.
MAKE SURE ITS OK TO USE THE IMAGE
Make sure that you have the rights to use any photographs you submit, it is best if it is one you have taken yourself.
I would recommend sending in a few images so that I can work with you to select the best one for your commission.
Enjoy the process of choosing the image, that expresses the character of the subject! contact me to get the ball rolling,