vector art is the art of drawing using the help of image software such as: adobe illustrator, coreldraw, freehand, macromedia flash, etc.
here are the stages I make vector art my brother's face, hopefully useful :)
Step One - Make a line
Make a baseline by following the photo you want in the picture
Step Two - Make eye line, nose lip
Then create an eye line with different shapes
Step Three - Make eyeballs
Just make the eyeball in as much detail as possible to look similar to the original
Step Four - Make lips
And proceed with making the lips with as much detail
Step Five - Make a color
Make the color as closely as possible, the most focused is the colors and shadows, keep trying to get the appropriate color
The last step - make a baground
after the picture is finished continue by making the baground for the view more interesting
maybe this is all I can present hopefully useful, the spirit in learning and continue to work :)