Probably one of the most important points is to establish definitions of words and phrases used.
- - - - - -
This cannot be stressed enough. UTLM.org has a great chart comparison. They will use the same words (God, saved, salvation, heaven, grace) and mean something COMPLETELY different.
Know what they mean and define everything you say. Instead of heaven say ‘Celestial kingdom’, instead of saved say ‘exalted’.