Of course, there are no real “rules” except for those given by the Lord! However, these are basic principles that are generally suggested to increase one’s success when contacting people. They are guidelines to keep in mind to facilitate our contact with them.
Remember, we plant the seed, we water it, but God gives the increase (1 Corinthians 3:6). In the end, whether a person obeys the Gospel will depend upon their own heart and what God does with our efforts (see Acts 16:14). We should do our best, but let the power of the Gospel do the converting (Romans 1:16).