First, and most importantly remember that you are dealing with a person, not some monster or demon. True, they are completely deceived by Satan, but they are a soul hanging in the balance and it could be you that "Pulls Them Out Of The Fire" (Jude 23). Be persistent and seek for more meetings, make them be the ones to cut off the visits. It is best to try to stay with one issue per meeting. NEVER argue at any point nor lose your patience. Jehovah’s Witnesses are trained to control the conversation and lead you down their line of questioning. Try to turn this around as much as possible, it’s easier to be on the offense than defense, especially when you know the direction you want to go. Ask questions that will lead to the answers you want. Suggested questions will be incorporated into the scriptured questions, you may formulate your own also.
One thing to keep in mind is that Jehovah’s Witnesses are brainwashed into believing that they are the only true followers of Jehovah. All of Christendom, as they call it, are nothing more than a part of "Babylon the Great, the Mother of Harlots" in Revelation 17:5. Every chance you get try to undermine the Watchtower’s credibility. This can be done by reminding them of false prophecies made by the Watchtower society and it’s members. An excellent book for this is "Index To Watchtower Errors", by David Reed. This book contains an excellent listing of false prophecies and supplies issue and page number of the Watchtower literature. If you do use these when speaking to a Jehovah’s Witness, try to use them as they pertain to the topic being discussed. You will need to memorize them, because you cannot use this book in front of them. Remember not to use any books by former Witnesses or Christian literature, as they will not listen to you. You can however use handwritten or typed notes with as little information on them as possible. The best method for talking to them is to use a copy of their own bible or a copy of an old Bible that you may have that you can write in. Make a chain reference in it with the Questions and Scriptures in this book, and make notes as needed on the page edges to keep your train of thought. This way you can stay with the Scriptures and go from one to the next to prove your point easier, more on this in a minute.