Kittens require a lot of fat and calories to grow normally. Until your kitten reaches adult size, which can happen between 7-12 months of age, it is best to feed them a high quality diet that is formulated for kittens, and as much of it as they want. If your kitten starts to become a little too rounded, then you cant start measuring out the amount of food based on the recommendations on the label of the food.
Quality of the food does make a big difference in your kitten's growth and nutrition. Not all diets available over the counter are good quality diets, and some can be hard for your kitten to adequately digest nutrients out of, which can actually predispose towards obesity and other health issues. Expensive also does not always mean high quality. Look for kitten foods that are meat based with high protein and fat levels. If you would like some brand recommendations, please call your vet.
Kittens imprint on food when they are young, so it is a good idea to feed them both dry and moist food on a regular basis. One way to do this is to feed them moist food once or twice daily, and leave dry food out for them to snack on in between. Kittens also do best with routine, so set up a feeding schedule that will work for you 7 days a week, and stick to it. Never feed your kitten first thing when you get up in the morning unless you want a furry little alarm clock 365 days a year.
You do not need to feed your kitten treats unless you want to use them as training aids. Kittens are very food motivated, so treats can be instrumental in helping to train them in multiple areas.
You also want to make sure that your kitten has plenty of access to fresh water. Cats are not water drinkers by nature, they tend to get the moisture out of their food. However, when they subsist primarily on dry kibble, they get no water from that, which is another reason why it is good to feed your kitten moist food daily since it is 70% water. But, that doesn't mean your cat won't drink water, so if you have multiple fresh sources of water for them, they are more likely to drink an adequate amount.