To begin, choose your puppy's favorite treats. If your puppy is very food motivated, then you can also use less exciting rewards most of the time, like your puppy's dog kibble, and save the tastiest treats for the hardest tricks.
Show your puppy a treat, then use the treat to encourage your puppy into the position, or into doing the activity, that you are training your puppy to do on command. For example, if you are teaching your puppy to go through a tunnel, then place treats in front of and inside the tunnel, to lure him into the tunnel. If you are teaching your puppy to 'stand', then when he is sitting, touch a treat to his nose, and then move the treat away from him slowly, so that he will stand up to follow the treat.
When you encourage your puppy into the position, or into doing the correct activity, then when he begins to do the correct thing, tell him the command word, and then right when he completes the command, praise him and reward him. For example, if you are luring your puppy into a 'sit', when his bottom begins to lower toward the floor, tell him "sit", and when his bottom touches the ground, praise him and offer him a treat.
When you have successfully lured your puppy into doing the correct activity or into the position that you are teaching him, repeat the process until your puppy begins to offer the behavior or position as soon as he sees the treat, as soon as you begin to lure him, or as soon as he hears the command.
When your puppy is doing the correct thing on his own, before you have lured him completely, then begin to phase out the lure. To phase out the lure, make the same motion with your hand or body that you did before when a treat was in your hand, but this time do it without a treat there. When your puppy has completed the behavior by following your motion without a visible treat, then reward your puppy with a treat from your other hand or from somewhere hidden, such as the treats in your pocket.
Practice without the lure, until your puppy can consistently do the activity or position without it. If your puppy is struggling, then give him a hint by luring him again with the treat after you have let him try without it for several seconds, or lure him again after you have tried for multiple times in a row. Do this until he does not need the lure at all, in order to perform the trick.
If you are using props such as physical objects, your hand, arm, or something else, to help your puppy perform the trick, then when he is physically capable of doing the trick on his own, understands the trick well enough to perform it when given the command, and is not afraid of any part of the trick, phase out the props as well. To phase them out, you can gradually remove them, or remove them all at once, and then put them back for just that trick attempt, after letting your puppy think about what to do for a few seconds, if your puppy needs a hint. You can do this until your puppy no longer needs any hints in order to perform the trick.
If your puppy is still depending on a hand signal that used to be a lure motion and you wish to remove the hand signal, so that your puppy will only respond to the verbal command, or if you wish to teach your puppy to respond to both, then you will need to phase out the hand signal. To do this, give your puppy the verbal command, then wait five to ten seconds before following the command with a hand signal, to give him a hint if needed. Do this every time that you practice with your puppy, until he will do the command before being given the hand signal. When he does this for the first time, reward him with extra treats. Practice until he can do it consistently.
Once your puppy has learned a new trick, keep practicing that trick often to help him improve even more, and to keep him from forgetting it, or from losing the balance or muscle strength that he may have developed in order to accomplish that trick. For example, if you are teaching your puppy how to limp, then the more you practice, the easier it will become for him to balance, and to not fall over while lifting up his leg while walking forward. Once he has developed this balance, you do not want him to loose it. Be sure to also make trick performance fun every time!