In summary, it is often best to not start with or focus on homosexuality. Let the Spirit of the Lord lead. We are never to be afraid of or shy away from any topic, so we are never afraid to declare the sin of homsexuality (sodomy). However, we have to realize this is not just a spiritual issue, it is a cultural, political, and community-based touchstone of our day. Therefore, it drags all of that baggage with it. Thankfully, when occasion requires, the sharp two-edged sword can slice through all of that and bring the real issues to light. But if our goal is to gain the ear and have the good news (and the bad, usually first) be heard, we need to ponder what is going on with these conversations.
I have found that discussing God's original purpose (whether preaching to a group or talking one-on-one), even going back to the Garden of Eden, and then discussing the course the world has taken can be effective. We have tried other approaches as well, as the Lord shows us how to engage our homosexual listeners. You see, homesexuals are generally much more socially and relationally aware than the rest of the population. So if you don't touch on homosexuality first thing, then you can often get the conversation going to where it needs to be: God and Christ. It has not been difficult to discuss morality and sin and such topics when we start this way. Later (in the same conversation), once they understand by our demeanor and discussion that we are not just there to condemn them, but want to have a real discussion, the Lord will often give more of an opening to talk about his standards of morality. Often we are able to end up talking about why homosexuality is a sin, but never have that as a goal. Don't speak as if homosexuals have only one sin. They are like the rest of us. They have many. I think sometimes the devil wants us to only talk to homosexuals about their sodomy. That is too narrow. God is concerned about everything.
Please be aware that this approach is not promoting being afraid to mention any sin, nor do we fear to pronounce God's judgment on any person because of their sin. But, motivated by a heart of compassion in Christ, we desire the whole message on the sinful life and God's answers to be heard. We have found this approach really opens doors to the point where we can discuss Scriptures with homosexuals, where other Christians were so cussed out by them in less than 60 seconds they had to leave, with both sides hating each other. That doesn't seem like the approach Jesus would have us go forward with. I don't see him approaching anyone that way in the Bible. There are a few listening ears out there. Show them your whole mission in life is not to announce to everyone around that they are going to hell. If you show them the love of God in Christ, they may not come to the Lord, but some of them might have a lot to think about that night. We have seen that happen. Always pray before you go.