There is no one definitive answer to this question, as every miniature Schnauzer is different and has different needs. However, some key tips for making your miniature Schnauzer happy include providing him with plenty of exercise and mental stimulation, ensuring regular grooming and baths to keep him clean and comfortable, and providing him with a safe and loving home environment. Miniature schnauzers are also very social creatures, so another great way to keep them happy is by ensuring he has regular contact with other people and animals.