This technique is a mish mash of a few tutorials on the Web. It looks like some really funky results have been achieved.
Find an image you like online or from your photo styash and print it off on a piece of paper. Search Goodle Images for a silhouetter eg 'galloping horse silhouette'. Zoom in to get the right size and trace off, even straight off the computer screen. The smooth, shiny side of the paper will face the the right side of your fabric.
Purchase Freezer Paper. It must be actual Freezer Paper.
Either trace or print your image to the Freezer Paper (on to the DULL side of the paper). If you choose to trace, place your image under the Freezer Paper with the shiny side of the Freezer Paper down, and trace. If it's hard to see your image through the Freezer Paper, try outlining the image with a Sharpie first.
Tape the Freezer Paper down on a cutting mat and cut your image using an Exacto knife. Cut the image out carefully, without cutting anything beside the image. Any cracks or extra cuts in the paper will allow paint to seep through.
Iron the stencil onto your fabric using a low heat shiny side of the Freezer Paper down. Make sure you iron around all edges of the stencil so that a seal is created for your stencilled image.
Purchase PERMANENT fabric paint from a craft store such as Tulips or Setacolour, choosing the matte option. If it's too thick, add a pinch of water.
Using a paintbrush, sponge or Q-tip, paint directly over the stencil, making sure the paint is spread evenly. You may need to apply extra coats, often up to 3. Allow each coat to dry for a couple of hours. Blow dry it if you're in a hurry.
Let the paint dry, anywhere from an hour to a few hours.
Carefully peel off the Freezer Paper.
FINAL STEP (and an important one you can’t forget). Iron over the paint to seal the finish. Note: stencils are not reusable.