Recently, I had the honor of painting a portrait for a newlywed couple. If you're up for a time lapse, here is the finished painting and the steps it took to finish it.
(Disclaimer: please forgive the inconsistencies in the coloring of the photographs. They were taken at different times of day, and it affected the lighting.)
First I sketched in the portrait with a grey watercolor pencil. Then I applied liquid frisket (the orange you see) over the areas I wanted untouched while I painted the background.
They're still a bit washed out. It's time to really hit the reds, shadows and details of the faces.