How do I "Crate Train" my dogs ?

I have two dogs Dixie ( Pit bull) and Toto (Schnauzer) and they use the bathroom in the house. Ive tried everything I can think of. Treats when they go potty outside stopping them when they are using the potty in the house tons of things maybe I can give this a try. While I am at work they are already in there crates. Thanks so much