Here is a step by step that was done at work and is a typical sample of how I do my portraits.

Step 1

Here I'm starting out with a mixture of light brown and golden yellow. All of my initial forms are painted with this one color.

Step 2

After the initial color is complete, I wash over it with golden yellow and flamingo pink to warm it up.

Step 3

Next I take my first color and add dark brown to it to further flesh out the hair and skin.

Step 4

The next thing I do is focus on the mouth and some added depth around the eyes.

Step 5

With that darker color I add some violet and more dark brown to finish off the hair and flesh. I also take opaque black and block in the clothes.

Step 6

The next thing to focus on are the details. Using opaque white, I highlight the appropriate areas within the face to enhance the light source. I also use the white to add the jewelry and then color it in.

Step 7

Here you see the finished portrait. The background is textured with burgundy and opaque black as is the lettering. Finito.