I would setup metrics of success like length of conversation, quality (which is subjective), and if you traded information to further stay in touch. Observing people wouldn't have such metrics. It is a discipline that you simply must practice. The key would be not to get distracted. You may wish to time yourself and set a goal to do it a certain number of times a week. It also helps with situational awareness which helps with being safer in public and being ready for a crisis should one arise.