If you constantly find yourself in workplace arguments, having to clarify what you said, or struggling to move people to action - your biggest barrier to becoming an effective communicator could be your awareness of your own communication shortcomings.
It is typical that when a person is confronted with a breakdown in communication, they tend to look external to themselves to the communication itself or their audience as the primary cause of the problem.
This is problematic as a fundamental principle of communication is that you can only control how you communicate, not how it is received and interpreted. In other words, you can't control how others communicate, just yourself.
Therefore, unless you have received honest and candid feedback from trusted colleagues, how do you know that aspects of your own communication style, skills, and acumen are not the root cause of your communication breakdowns?
The solution then is to seek out 2-3 trusted advisors who you truly believe are highly effective communicators and ask them to give you their honest and candid feedback on how you come across.