Cats make the best pet because they are self sufficient. Unfortunately not all of them are the same. Some are more temperamental than others. It is crucial that you understand how to train them while they are kittens so they do as you wish when they are cats.
The first thing you should do is understand the kind of training to utilize on them. They have different personalities and some may withdraw into themselves or act aggressively to the wrong training that you try to use. Endeavor to honor them with food or affection - whichever is the best motivation for them. Remember that hurt is not a form of punishment that should ever be used on animals.
When you are training them you have to get on their eye level. This will show them that you are being serious and they will pay more attention. When they misbehave it is frequently assistive to use a plant sprayer or water gun full of water. Most cats do not like water and will understand immediately. Spray them when they do something wrong - but don't yell at them.
If the water is not helping than you need to try to surprise them. Keep a bean bag close to throw near them if they do something wrong. Make sure that the bag will not hit them in anyway. You are only attempting to surprise them and stop whatever they may be doing. Do it instantly! If you wait till they finish they will not understand why they are in trouble.
If you are experiencing aggressive cat behavior problems than the best thing you can do is to tap lightly on their nose. Remember that pain is not an option. Only tap on the nose and speak to them in way that makes them know that biting and scratching is not permitted.