I hate doing these but I know how you kitties want your whisker thingies!
Step 1: take some duct tape and make a canvas. Draw the spot pattern you would like to create a stencil.
Step 2: take a craft knife and out out the pattern
Step 3: place the pattern sticky side down on the fursuit head
Step 4: airbrush over the stencil (you may also try a foam brush with black acrylic paint watered down
Step 5: count to 15 and then remove the stencil and take a slicker brush and brush along the muzzle to create a more streaky look
Step 6: clean off the stencil and make sure there is no wet paint.
Step 7: flip the stencil to be sticky side up on the opposite side and repeat steps 1-5 !
I added some smaller spots in front after by putting the tip of the airbrush super close to where I wanted and lightly applying pressure fir super short burst.