Relational evangelism is much more effective than cold-calling on stranger's doorsteps. What I mean is that you seek to establish relationships with non-Christians that do not center on converting them. This is the first step. For example, you invite a coworker home for dinner or go bowling with him. Overtime, as the Holy Spirit leads, you begin to share the gospel with him. That is the second step. This method is most effective.
As for cold-call evangelism, it can have its place. However, one needs to moderate one’s tongue and speak respectfully. One Jehovah’s Witness, who answered this very question, is fond of calling Trinitarians “Satan worshipping trash” who will be “destroyed by Jehovah at Armageddon.” Rude comments like this are much less effective when trying to reach the lost. This is why many true JWs on here have labeled him a “bad associate,” a “poser,” and have blocked him from answering their questions. Basically, his reputation as a worshipper of Jehovah has been ruined. And whose fault is this? It is entirely his own fault.
Edit:
@ Jehovah Boy: You deny that you call people Satan-worshipping trash? Well, I’m a bit too busy to sort through your posts in the comments sections where you frequently do that. Anyway, once I post the link, you will no doubt delete the comment in order to hide your behavior. However, here is a link where your brothers and sisters make these comments about you:
https://answersrip.com/question/index?qid=20100331081624AAVMkAO&show=7#profile-info-AA10024451
I have emailed you 3 times and other witnesses are concerned with the way you are behaving. You just cannot go around calling people idiots or keep commenting on their lack of education or grammar! I am ashamed to call you my brother and that hurts!!! You said that you are a ministerial servant. Do you honestly think that being one gives you the right to be rude to others? I just feel plain angry that you are behaving in this manner when you are supposed to be showing love. Doesn't it bother you even a bit to have even the people "on your own team" complaining so much about your Qs and As?
And here’s how you responded:
Tuppence, I am seriously questioning your claim of being a Witness. And Vot, please spare me the "and many others" nonsense. Like Tuppence, I already question your claim of being one of our "sisters" in the faith.
Then another brother responded to you as follows:
The spirit in which you are handling the answers to this question bothers me. Vot happens to be a very dear sister and I don't think attacking our brothers and sisters is admirable. Don't bring reproach to Jehovah's name with this show of hostility.