I've searched through the FAQs and help, but never seem to get a grasp on how to breed deviant pets. I own some, and have even bred some by a random chance. There's been instances where I've bred one of my pets to another, and out pops a deviant, even though neither of the parents were deviants (recessive maybe?).

What's the actual way to breed one? I have both a 50% DCA and a 100% DCA but I don't want to put either of them to waste by putting them on the wrong pets.

Look at the Skin Color and Skin Pattern genes. They should be doubled, i.e. the dominant (green) and recessive (grey) genes are the same.

For example I have a unicorn mare who is White/White and Cream/Cream. If I bred her with a stallion who was the same genetically I'd have a 10% chance of getting a deviant offspring in either  white or cream (or both, a double deviant).

You would have to use a 50% or 100% DCA on a female with this "homozygous" (double) colour genetics, who'd been bred to a homozygous male, in order to get deviant offspring, and even then in the case of the 50% DCA there's a chance it won't be deviant.

Hope this helps :)

Just to add to this - you can NOT get a double deviant from two non-deviant parents! To get double deviants you need one parent with a pattern deviation and a colour deviant parent. See FAQ: 

The only way to breed a pet with both deviant color and pattern is to choose very specific parents. One of the parents should have deviant color and the second one should have deviant pattern. The chances of getting a deviation on each color parameter still remains 1/10 so the babies with double deviation are extremely rare and valuable.

Oh ok, I thought double deviants could happen from non-deviant parents... You live and learn *^_^

Same. Lol