What are the best ways to improve your body language?

Just give it some time, body language isn't something easy to change, because it is like the scars of a warrior that shows all his past battles.  Truth! You'll be more attractive, more confident, appear more trustworthy, more intelligent, more valuable and because of all this, people will treat you MUCH better and respect everything you do, and the best part is that you won't have to say a word. Body language is truly one of the most important skills someone can develop.

1-RELAXATION

conveys only good qualities and control, which means that you are assertive and a high status person. Always focus on all your body tensions, and release them. Visualization, meditation, and so many other things may help, loop up for ways to become truly relaxed. Bear in mind that most people they don't really know what it is to be truly relaxed. Proof of this is a technology called biofeedback, in short, it analyzes through precise measurement equipment how relaxed your body is.

2-SLOW MOVEMENTS 

One of the best ways to portray relaxation is moving slow. It is something quite hard to be done. If you think you are not doing things in a hurry, you probably are. I came to realize that the majority of people move too fast. This is one of the best giveaways to tell if someone is important or not. Try to slow your body language and pronunciation as much as you can, really, as much as you can. This is my second best tip to anyone.

3-BE STILL AND MOVE DELIBERATELY 

 Being is still is one of the most underrated things regarding body language, the more still you are the better people will look at you. What I want to say is that when you are using the computer or reading a newspaper, or watching TV, the less you move, the more control and self-assurance you show. With that said, try to move deliberately. Being confident is not about doing something, it is actually about NOT doing the wrong things.

4-NON-REACTIVE

The less you react to the environment around you, the more you appear to be in control, poised and with every aspect of your life handled.

5-GOOD POSTURE AND BEING OPEN 

Try having good posture at all times and also being open, avoid any leg-crossing or arms-crossing behavior. Even when you are at home watching TV. This will have an amazing impact on your energy, you will feel better after this becomes part of you. You will feel more energized and ready to do anything just because your body feels it is not closed off. This one is a must.

6-AVOID SELF-TOUCHING 

This means that if you shouldn't touch your face, rub your hands, or anything else if you don't NEED to take something off of your face for example. Don't try to find reasons to do that. "...But I did that because it was itching." As it turns out, even when it itches you should avoid doing that. If you read some books about body language, you'll find out that sometimes your nose itches or some part of your face because of increased blood flow in your face (sign of nervousness)and subsequently you're touching your face because you want the itch to stop, but actually you're touching it because you are nervous. This goes for any part of the body that you feel you need to touch when you are under pressure. So, avoid at all cost letting this become a habit for you.

7-USE SOME SPACE

Territorial displays are one of the best ways to portray confidence and high status. Have an expansive body language, use the space around you. This is a sign of being relaxed, and being relaxed is CRUCIAL to amazing body language.

8-USE A DIFFERENT PERSPECTIVE 

I know it's a little hard to imagine, but imagine you could see your body language through other people's eyes, how would you judge yourself? What assumptions would you make? This is one of my greatest discoveries to get my body language to the next level. Trying to do this has allowed me to notice and change some things that I wasn't paying attention, I could understand what I was doing wrong. Seriously, this is one of the best ways to get better, after a while practicing the other things try implementing this one.

9-DO AS LITTLE AS YOU CAN

doing something, the less effort/muscles/movement you put into play the better it'll be and look like. This is the basis for awesome body language.

10-ANALYZE

The last tip, isn't really a body language hit, but a behavioral one. Try paying attention to people deliberately. Try using these patterns that I showed you to guess who's the boss, who controls the relationship, who is the most important person in any given setting. But not only this, look out for people that you think that have good body language, be it in the movies or with your friends. The more you pay attention, the better you'll become! 

by reading a book or join a training for body language

Good examples given by Mrs. Ghada , i support her answer

Read books about body language , read articles, attend many conferences, expand your network of knowing people, , and start to apply that knowledge on your family first then friends then teammates finally starngers to know where you stand 

thanks for the invitation.....................  leave the answer to experts,

I leave the answer to experts, thanks for the invitation. .

I leave the answer to experts and specialists in this field .