Browse through my portrait cateogories to get some ideas, then look through your pictures and pick out your favourites!
 
A higher resolution photo, or scan of an old photo, is usually needed to be able to capture the right details. A good indication of whether I can work from it is if you can zoom in and it is still clear. I have also had success in recreating old photographs and photos that are slightly pixelated. When in doubt, email them to me and I will let you know if I can use it.