Hold a treat in front of your dog’s nose and motion up and back at a 45-degree angle. Your dog will follow the treat, bending her head back until she sits. Say yes or click and then reward them with the treat. Repeat this a few times. Next, show her the treat, but don’t lure her with it. Wait until she sits on her own, then click and treat. Repeat this until she immediately sits every time you show her a treat.
Use this in conjunction with the “sit” command. As your puppy sits, hold your open palm in front of her face and say, “Stay” while you hold the leash with your other hand. When she stays for a few seconds, say, “Good stay” and treat. Repeat a few times. Gradually move further away from your dog and increase the time you ask her to stay. This command is crucial in emergency situations. Let’s say you’re visiting a local park with your kiddo and he or she takes a tumble off a swing. You can put your dog into a “stay,” and go help your child without having your dog suddenly invading another family’s picnic, or running off and getting hurt.
Hold a desirable object in front of you in the palm of your hand. When your dog reaches for the object, close your hand and pull away and say, “Leave it.” Repeat this step until your dog stops reaching for the object. Now, place the object on the floor. If your dog reaches for it, cover it with your foot or hand. When your pup consistently leaves the object alone, add the cue, “Leave it” just before you present the object. As soon as she backs off, click and say, “Leave it.” This command will enable you to stop your dog from engaging in things like discarded chicken bones, toxic plants, or an unfriendly dog.
Start with your dog sitting. Hold a treat in front of her nose, and motion with it straight down to the floor between her paws. She most likely will follow the treat to the floor, lying down as she does. As soon as she is lying down, click and give her a treat.
You can start by training "come" after "stay" on the leash. If he doesn't come at first, give him a little tug on the leash and when he takes the first step towards you praise and reward. He will soon start coming on command.
Turn training into play time by using the classic children’s game of hide and seek to reinforce the “come” command. Practice this game inside your house. Have someone hold your dog while you hide in the house. Then call your puppy by saying, “Come!” You may need to repeat the command a few times before she follows your instruction. Once she does, click and treat. This is a fun way to teach the “come” command, and it also teaches your pup persistence. If your dog takes after a squirrel into a busy street, or if you get separated from your dog in a crowded area, using this command can avert a potentially dangerous situation.
When your pup is a little older, take him/her to dog training classes to learn to lead, heel, and other useful commands and games.
Training is about more than just safety and good behaviour. It provides enrichment and stimulation.
Schnauzers can be stubborn but they are very intelligent dogs and definitely thrive on good training.
For issues with dogs, I'd recommend Cesar Milan.
There are plenty of other trainers with different philosophies and techniques, so you can choose what appeals to you.