Effective communication is intentional. A simple tool for speaking assertively and authentically is using the "I" statement. Here is an exerpt from John W. Jacobs.
At the heart of better communication is the self-statement. A self-statement puts the responsibility for your emotional experience squarely on your shoulders. It is one single, easy-to-learn skill that can most dramatically improve the communication.
Self-statements always begin by using the subject "I" to discuss a problem. They exist in opposition to their nemesis, "you" statements. A "you" statement puts the responsibility for your emotional discomfort on your partner, never on yourself. "You" statements are communications of criticism, blame, and anger. In "you" statements, your emotional experiences and negative behaviors are always presented as being an appropriate response to the irresponsible or hurtful action of someone else. "I" statements decrease the emotional reactivity of the system. "You" statements increase the emotional reactivity and interpersonal tention.
That's a very wordy way to say this - OWN your opinions. OWN your emotions. Use of the "I" statement. It will help you communicate more effectively.