If you and your cat have a very strong bond, you will find out that you're developing a very individual way to communicate with each other. Imagine you would live with a person who's speaking a foreign language: To communicate, you would watch that person's facial expressions, body language and gestures very closely, and after a while, you will recognize certain words and associate them with certain situations, even when you're not speaking the language.
This is how you have to look at the feline/human communication. Cats have learned this a long time ago when they found out that meowing is a good way to get a human's attention. Adult cats would communicate with each other by using more subtle sounds, but felines that have grown up with humans have learned that a loud voice helps them to get what they want. It doesn't matter if it's a yummy treat they desire or some moments of cuddling - a pitiful meow guarantees immediate success! The sooner a kitten makes this experience, they more it will use its voice later in life - and the human will learn to tell the different sounds apart and associate the correct meaning.
What cats are able to understand...
On the other hand, it always amazes me to see how cats are capable of learning certain words of the human language, and even to recognize short sentences! Of course it will help the cat when you're always using the same words in the same situation, and in the same tone, i. e. when it's feeding time or during a playing session. You will find out that a cat will even remember things it has learned a long time ago: Once I mentioned the name of a game which I haven't played with my Luna for more than a year, but when she heard that name, she came running, eagerly meowing and ready for a playing session - the same reaction she used to show when I brought that particular toy. She remembered the name - and its meaning!
Besides, cats are even able to recognize the meaning of a human word when it's NOT used in a familiar situation: I once lived with a cat that came running when I offered a visitor something to eat. The cat immediately recognized the word "eat" and ran happily to her bowl ...
In my opinion, it's very helpful for a better understanding to adopt some elements of the feline language and body language. However, this does not mean you have to meow loudly in different tones, even though this may be an interesting experience! ;-) But I've noticed that - especially when you have to deal with the activity of overstimulated kittens - some hissing and growling may help to show them their limits. This is exactly what the mommy cat does when the little ones are going too far (see also Cats need to be punished?
Greeting each other ...
We can also learn a lot from the feline greeting ceremony. When two cats meet, they sniff each other's nose - as a human, you can offer your outstreched hand instead, so the cat can make the first contact. It's also recommended to kneel down, especially when you don't know the cat very well, or when it's very shy. You will look smaller to the cat that way, and less threatening.
It's a big mistake to approach a cat in a pushy way or to pet its head and back without its agreement! Cats do not appreciate obtrusive behavior or being stared at, it annoys them or even scares them. However, as far as staring is concerned ... When you already have a good relationship with your cat that's based on trust, the cat will tolerate staring and being looked at. Obviously it has learned that there's no threat coming from "its" human.
But instead of looking straight into the cat's eyes, you may try to blink. This is a friendly gesture in the feline world, some people even say that it's the cat's smile. However, many cats do react positively to this kind of eye contact - they'll blink back at you, or even walk over to you, looking forward to a cuddle session. Just give it a try, it's amazing!
I think we still have to learn a lot about the communication between cats and humans. It's a process that's requiring a lot of understanding, intuition and observation, but I do believe that the human/feline friendship will truly benefit from this.