Shino is designed to be applied irregularly. Apply two irregular coats. Once you have used it awhile you will see the effects you can get by varying the application.
Here is how AMACO's ceramic engineer George Debikey describes how to control them through their application:
PC-50 SHINO needs to be applied irregularly. Apply 2 irregular coats. You can produce the reduction type flashes where you apply it thicker on the piece, but do not exceed the two coats thickness. Spraying PC-50 Shino is also very proficient. You will need to spray a very thin irregular coat with heavier application on the areas of your piece where you would like to see the reduction type flashes. Most importantly; experimentation is the key to finding new effects that you can call your own. NOTE: Always wear a mask when spraying.