On the wall at my grandmother's house hang large photos of her children taken in the 1960s. The technique at the time had the photographer take the pictures in black and white and then, after development, color them with watercolors. I loved the affect and have found a similar (much easier) way to duplicate it with chalk.
Next, I went over the skin again, this time with light pink. It gives the skin a bit of a glow and tones down the yellows in the beige.
And you're done! A customized, vintage photo transformation is as easy as that. This technique works great with photos of babies and kids too. Moms always love a custom card or scrapbook page with this soft finish.