Believe in yourself. Often it happens that you have something to say, but for some reason, you stand aside and be silent? Stop thinking that your thoughts and ideas are less important, and unique, than the ideas of your friends or colleagues. Every person is interesting in its own way, so don't be afraid to show people your personality. If you do not begin to say what you think, you always have to say what you want to hear. The same thing will happen with the action.
Start talking. Select the day and say anything that comes to mind, of course, within reason. If you find this task is difficult, try to limit it to one sentence. This does not mean that you have to say once what I think. You need to voice your thoughts at the exact moment in which I wish I hadn't, knowing what to say. The next day, increase the number of phrases.
Resort to interior monologue. Ask yourself, why didn't you say at one time or another, what you thought. What exactly prevented you? If it is shyness, modesty, self-doubt, fear, the need to actively fight. As soon as something from above becomes the cause of your silence, try to overcome himself and to Express his opinion. The less you fight it, the harder it will be to start to say what you think.
To say everything is also not the best option. Each time before you say anything, think about whether you want to say it, do not spoil this relationship, will not hurt your career, would it not be used against you. The saying "always think about what you say but not always say what you think", has not been canceled.
Try to Express your thoughts as often as possible: at work, with friends, in public places. Over time you all must succeed.