This is only the second forward-facing unicorn that I've made.  When I was searching for unicorn ideas, this image came up on Pinterest.  I fell in love with it and couldn't resist making it.  What I really liked about this unicorn was the rainbow outline; I wanted to replicate that most.  

I created this cookie by printing out the image of the unicorn to the desired size I wanted.  Then I cut it out and used it as a template to cut out the cookies.  I took white piping icing and piped the outline.  I didn't want to deal with cleaning my airbrush machine, so I used Wilton's color mists.  I used pink, yellow, green, blue and purple.  I have an image below of what it looked like after I sprayed the cookie.  The image shows where I sprayed each color.

Then I flooded the body with blue-green icing.  The next day, I added the mane and tail with a mixture of pink and purple icing.  Once the mane was dry, I piped on more blue-green icing for the horn.  I added the pink nose and lines to the ears and black eyes.  I had to pipe a white line between the tail and body.  When it dried, I painted some blue and green food coloring on.