Payment guarantees results.
The more you reward certain behaviours, the more likely your puppy will offer that behaviour in future. It's worth mentioning that payment doesn't have to be in the form of food. Toys, praise, attention, being allowed off leash, invited up on the couch, all of these thing (and more) can be used as a reward for good behaviour.
Like having a quiet, calm pup at home during the evenings? Praise and reward that behaviour like non-other. If your puppy only receives attention for the bad behaviours, they will quickly connect the dots...chewing, barking, and jumping-up gets results!!
When using food as a reward remember to keep them small and tasty, if it needs chewing it's too big. I often use Ziwi Peak in class, breaking up the small square pieces into 3-4 bits to maximize my number of rewards. Ziwi Peak is a fully balanced food, so if you're worried that your puppy is eating too many "treats" you can easily cut back a little on their daily kibble and they wont be missing out on any vital nutrients.
Think of the Clicker as a camera, not a remote control. With the Clicker you are capturing the perfect moment, such as beautiful eye contact on a busy street corner, or sitting patiently while you open the front door. Your puppy is working hard to earn that click and treat that follow.
What not to do. The Clicker is not for getting your puppy's attention if they are ignoring you. Instead, see if you can encourage an easy behaviour that is worth rewarding, such as eye contact. If your puppy is ignoring you, trying making a smoochy noise to get their attention, as soon as they make eye contact, you can click (which will really get their attention) and follow up with a treat.
Three Strikes and You're Out!
This applies to you, not your puppy. If you've tried something twice and it's not working for you, you only get one more go so make it as enticing as possible. Chances are your puppy is either distracted by something new, is loosing interest, or you're asking for too much too soon. Take a break, have some play time, or move to somewhere less distracting. Your puppy isn't being disobedient, they just have a really short attention span...so no point getting stressed over it.
Body language before voice.
Your puppy pays way more attention to what your body is saying vs your voice. For instance, if you are saying “Sit” but the hand holding the treat is bouncing up and down, you are actually asking your puppy to jump up.