It's on the Lil Beginnings site and is by Laura Tennill. I just googled show clipping miniature horses and there it was. There is a picture as well.
Miniature Horse
Information Pages
Show Clipping your Miniature Horses Head
by: Laura Tennill – Ten-L Training Center
First of all, I would like to say there are several ways to clip a show horses head. This is the way that I like to clip the heads of our show horses and it is the way I would recommend to those wanting to achieve a smooth clip job that will accentuate the horses facial features.
When show clipping your horses head you can make a dramatic difference in his appearance by using a combination of different sized blades. I use a combination of #30, #40, and #50 blades. Always keep your blades clean, sharp, and well oiled for maximum results. Make sure you have your blades sharpened as needed and on hand well before the show so you will be prepared. Using the different blades will contour your horses face really nicely.
We normally clip our show horses heads very close to the day that they show. I like to shave their bodies first a few days prior to the show, and come back and do their heads one to three days before the show, depending on their color, and personal preference.
Begin by clipping your entire horses head in a #30 blade going against the way the hair grows. Use a light but steady pressure on your clippers making even strokes. You can lightly blend the area behind the ears into the area where the head joins the neck by turning your clippers around and blending in the direction the hair grows, do just a very small area behind the ears and down to blend head and neck area well. I normally use a #15 or a #30 on the body of the horse so it will usually blend very well there. Clip the outside of the ear, unless its white, with a #40 down to the base. This really makes the ears look sharp. Keep in mind that any moving part of a horse will grow hair more quickly than the other area. The base of the ears is one of the parts that grows the fastest. It will blend well with the #30 you have used on the head. Clip the outside edges of the ear in a #50 and the inside of the ear as well. This will really take the hair and will look good and clean when showing, using a light oil inside the ear right prior to your class! Take a #30 or #40 blade and go over the throatlatch area underneath your horses neck, just where the head joins the neck and the area where the hair grows in a swirl. This will make that area look really neat and clean. Use a #50 under the entire horses lower jaw, looking under there to be sure you got all the hair there as it would be very distracting with a show halter on to have hair on the jawline.