Actually, taming a kitten is not that difficult. It doesn't matter whether it's wild or not. All kittens are innocent, naive and just starting out with no knowledge. They are in "learn mode," just as youngsters of other species are.
The variable factors to consider are age, health, environment and whether the mother cat is present. A kitten born outdoors without benefit of human contact will of course become a wild adult, and taming at that time would be difficult, it not impossible. This is even more difficult if the mother is wary of humans and won't let you near her kitten(s). If that is the case, the taming process will include her, too. But for now, let's assume the kitten is alone.
Since even a wild kitten can be overcome by a human, a good first step after capture is to get a health evaluation.
Once the little one is certified healthy, you can begin by keeping him or her in a cage. It must be large enough to allow room to move around comfortably and still have access to a bed, litter box and food dishes. If you've acquired the kitten from a wild environment, the cage is the best way to start. This decreases the size of their known world and gives them the opportunity to examine it and get used to it, but more importantly, to learn that you are the giver of all things...food, water, warmth, security and comfort.
If there is more than one kitten, they can be caged together for security and comfort if they are very young. If older, it's better to cage them separately so you are the primary caregiver. This will help the kitten get used to you and eventually bond with you.
Since a wild kitten has no experience with being touched by humans, the cage experience will help you to demonstrate that your touch can be comforting and trusted. Just don't betray that trust.
Begin by reaching into the cage either with a gloved hand, or a brush, such as a simple one-inch or two-inch paint brush. When the kitten bites or scratches it, you'll see why you're using it. The kitten needs to get used to being touched. Gently stroke along the back and the head, imitating the licking movements the kitten would normally receive from its mother. In time, as the little one learns that your hand is a source of comfort and that you bring nice things, like food and water, you will be able to use your bare hand. Work with the kitten many times a day to help him become accustomed to you.
Since kittens learn quickly, you should be able to hold one in both hands in less than a week if you've been working on gaining trust. But this is not a sign that it's time to let him run loose. He will need to stay in his cage for at least another week, perhaps two, at least at night when you're getting some sleep. If left loose in the house too soon, you may have a time locating him the next morning.
Once he's accepted that you are in charge and taking good care of him, it's time to play with him to help build a bond of trust and enjoyment of each other's company.
You may have to experiment with the types of toys that interest the kitty, but in general, they enjoy batting at things, and "attacking" something dangled or dragged along in front of them.
You can also leave a small stuffed toy in the cage while he's still confined, to give him something to play with, snuggle with, and to look at when you're not around.
When cleaning the interior of the cage along with the items in it, you will have to put the kitten into another cage, or pet carrier, or have someone hold him firmly but gently while you quickly clean things. If there's still a chance of being bitten, use heavy gloves to move him into another container until his cage is ready. However, small kittens are quite easy to manage by simply grasping the skin on the back of the neck, as the mother does when moving one.
Realistically, if everything goes well, you can expect to tame a wild kitten within a few weeks.
