Teaching your labrador puppy to ‘sit’ is easy and very rewarding. You’ll need some high value treats in place free from distractions with your puppy on a loose leash.
Lure you puppy with a high value treat, positioned between your thumb and middle finger.
Raise your hand (palm up) over the dog's nose so that they follow the treat and look up. As your pup looks up at your hand, they will automatically sit. When their backside hits the floor say ‘yes’ and release the treat. If I give the hand signal with my right hand, i’ll generally offer the treat from my left hand. This tends to stop my puppy from anticipating and chasing the treat.
For the first 20 repetitions, simply ‘mark’ your dogs behaviour with ‘yes’ and immediately (1 second) reward them the treat. After 20 reps your dog will have worked out the relationship between the ‘lure’, ‘sit’, ‘yes’ & the ‘reward’.
When your dog is reliably following the lure into the ‘sit’ position, continue to lure them into the sit position and add the "sit command" just as they start their movement.
With this degree of progress, you can continue to use the same motion but now, with an empty hand, palm up and say "sit". If they sit, mark the behaviour and give a ‘jackpot’ of 3 treats.
This is the ‘hand signal’ and will be the que for your dog to sit. Be sure to say sit before your give the hand signal.
Practice the ‘sit’ at feed time twice daily. And increase the duration of the sit. This is called the ‘ sit stay’.
Slowly expose your dog to the ‘sit command’ with increased distraction. For example, practice training your dog to sit when someone else is in the room.
You should advance to situations where other dogs or animals are nearby.