When a dog doesn't do what I ask and is a puppy in training I think of a few things I need to alter.
Higher rate of reinforcement, rapid click/treats. have you loaded the clicker well enough just clicking/treating until it's well established. maybe little refreshers daily at first. otherwise don't give the dog treats for nothing. most puppies have a default behavior which is often a sit since it allows them to easily to look up at you. this is your chance to say sit just before and c/t.
Good GREAT treats that are meaty and stinky-not boring kibble which may discourage concentration
small quickly chewable non-crumbly pea sized treats already preloaded in your hand for very fast dispensing--no fumbling noise or time on bags, pockets that will distract from the click and immediate treat. you don't want scrambling to clean up crumbs. also don't recue when the dog is still chewing b/c they won't really be listening yet.
puppies have a 1-3 second attention span so you need to work within that. you can't say sit and wait 5-10 seconds then click and treat
does the dog know the behavior before you introduce the verbal cue?
remember clicking ENDS the behavior. so if you click sit offer the treat a foot away from the dog's nose so he has to get up to go get it. he is then primed to sit again very fast and be clicked and treated again faster. you don't have to get them up and then get their attention etc b/c you already have it.
i agree and disagree with the don't repeat-it's a more traditional view of things but you don't want to say sit sit-SIT and teach your dog that sit sit SIT is the cue to SIT. in shaping training you can recue if you reset and wait a bit twice. if i ask my dog to pick up a ball and she doesn't, i may move the ball and recue her, or walk to the other side of the ball and recue her. what i don't do is just stand in the same place doing the same thing and repeat. i really don't think if you're doing everything else right this will be an issue.
two related things to avoid..don't over use the dogs name b/c it looses meaning and it's pesty and annoying after a while. fido,,fido FIdo FIDO fiDO sit. don't be a pest. try to understand that you are in competition with the world to be most interesting to your dog. figure out that ever you need to become more interesting. If it means a toy or bouncing ball or a tug, making funny noises and running backward a little to entice the dog to follow. Most likely if treats are coming at a high enough rate and you are finding something to reward or get attention you'll have the dog doing something in response to you. will revving your dog up make things better or staying really calm? see what works.
are distractions low enough-are you alone in the house or somewhere that there aren't bees and birds and dogs and people?
are you keeping the training sessions short enough?? 1-3 minutes
are you ending on a good note and not wanting just ONE MORE. and ending when puppy is still raring to go not when he loses interest and wanders off. you want him raring to go next time.
are you playing a fun game after training and taking breaks if he's tired or having an off day?
are you luring first-waiting until puppy will do the behavior like sit every time and clicking right as the butt hits the ground and treating within 1-2 seconds. then get rid of the treat in hand and use just the same hand movement - same everything. when you can bet the puppy will sit say sit just before he starts to make any moves to sit and do your hand lure with the empty hand. same c/t. then try saying sit wait 1-2 seconds and if puppy doesn't sit do your lure hand gesture but smaller and smaller over time then fade it all together. I prefer to teach verbal first since dogs are more visual or hand cue oriented than verbal. if the verbal is solid first then it will be better remembered over time.
remember the dog listens to the first cue you offer (hand or voice) and disregards all that comes after most often. he may preferentially ignore voice and take the hand gesture no matter what order. are you training exclusive hand and voice separate sessions? this helps them learn both faster.
are you changing it up some---not the same routine every time or they will learn to anticipate and not think. fade the lures asap because a lured dog isn't learning they are just following. once the dog can do the behavior get rid of the lure and ask for some thought on the matter. keep treats out of any hand u use to do cue with. keep hands and body still so you aren't unconsciously giving other cues the dog reads that you aren't aware of. practice being a statue and say sit if your dog already knows sit. many people don't realize they are bending forward and the dog is cueing this and ignoring the sit verbal cue. don't move those hands put them both behind ur back and click from there. the less confusing or mobile you are the less the dog misreads you.
most people don't fade treats fast enough. if you offer 100% reinforcement all the time the dog learns why should i do this now when i get a treat for it if i do it in 2 minutes or when i feel like it. work on leash for a while so the dog can't wander off. stay up and happy and positive. the second u feel frustrated STOP and wait until later. i fade the treats for a quickly learned behavior when the dog does it very reliably 97% of the time to every other time. i also change up where they are. they may be in my hand, just out of sight on the cabinet where quickly accessible, or in my mouth so i spit it at the dog and taught her to catch it. we learned that in agility and it's great for keeping concentration on your face. you can show the dog the treat in ur mouth or close it and hide it...be tricky. as long as you are successful keep fading the treat to random. if compliance goes down boost the treat rate back up.
set ur dog up for success, don't expect a come during the middle of a full blown romp with a doggie friend or during times of very high excitement. call when you think there is a good chance he will come or sit or whatever.
All just things that I tweak a bit to help my dogs succeed. When i teach new things i click treat very very fast and have a high rate of reinforcement. it's a very successful technique.