When we try to change others, we are attempting to persuade them. Many of us are looking for the best methods to change others and we tend to concentrate our efforts in a narrow fashion. Allow me to suggest that the most powerful device for changing others is available to all of us.
If we divide the world of communication into two parts it will facilitate our thinking: 1) verbal communication and 2) nonverbal communication. If we examine how we learn to do much of what we do we will discover that it we learned through observation, or non verbally. If we examine which of these two processes individually in our own experience we will discover that we trust most often "what you do rather than what you say."
Another aspect of communication is that the impact of communication tends to build over time. It isn't what mom told us to do once, but a thousand times. That still is no guarantee that we will "do" what mom said we ought to do. On the other hand, we probably will remember it very well. Later in life, when it seems that what mom was advocating is the best course of action, we may adopt part or all of what she tried to persuade us to do.
If we put these ideas together we should discover that the most powerful attempts to change people is by our own example. As our non verbals are "heard" over time we begin to assemble our changes based on the observed evidence. We become changed. The person or persons who started the process of change (persuasion) may never know the role they played in the change. Never be discouraged that your attempts to elicit change have "apparently" failed. There is no way for you to know that.
But, there is a huge problem attached to all of this discussion. What about one of the most prevalent and obvious attempts to change our behavior: elections. Since most of the candidates are not personally known to us through day to day observations and since they can allow certain well chosen bits of information to flow through the media, we end up making choices based not on personal observation. Instead we make them verbally, know full well that we don't trust verbal communication nearly as much as we trust nonverbal communication.
This should force us to look for outcomes, performance records uncontrolled by anyone, on which to base our changes. Here we are very weak. We tend to ignore history, even recent history, and choose based on the weakest data, verbal. We play a major role in our own changes. Take the time, energy and focus to change (persuade) yourself that you deserve. Don't allow anybody's words alone, even mine, to change you when more can and should be done.