In my case, when I try to change some undesired behavior, mental exercise provides a temporary solution but usually no sustainable results.
The good news is however that undesired behavior (ultimately) always translates into some kind of physical discomfort. Growing an ongoing awareness of these (small or large) discomforts in a compassionate manner somehow activates behavioral change in a healthy and sustainable way. Main reason being that physical discomforts are easier to spot, allow a more objective analysis and more difficult to hide or disregard than mental discomforts.