If you're consistent, and always make them sit, they'll sit automatically. Titbits are useful as rewards, and as lures, to attract and keep your dog's interest. They should be small, and smelly titbits are especially attractive. Try out different types of titbits - dogs vary in terms of how they respond to them. The titbits have to be small so that they can be eaten fast.
Most complete food comes in small enough sizes to be used as titbits.
Titbits are especially useful for early training, and your first walks with a pup or new dog, to reward the dog for coming back when you call, and for sitting quietly when humans or other dogs are around. You can replace one of his meals with the same amount of complete food taken on walks, so that he doesn't get too fat and has more incentive to work for food. As your dog becomes more obedient, you can cut down on the titbits, though they can still be useful for teaching new skills to well-trained dogs. Negative reinforcement Dogs also learn fast from negative reinforcement, but not always in ways that you intend. Shouting at your dog when it barks and lunges at another dog may just make him more nervous when he sees other dogs approaching, and more inclined to bark and lunge.