You haven't met a Christian that you like then? That sounds pretty sad. There are many people I see that are an inspiration to me. Both Christian and nonchristian. But the Christian one's are sometimes extra inspirational because they've applied bible verses to their life, and have given me something more to live up to and strive for with life and faith.
As for ques, can you rephrase the question? There are ques we see in people in general from intreast and dis-intreast, trustworthiness and caution, to seeing simularities and a potential bond, as well as ques to invoke our sences of wanting to help someone.
Most of these ques are something we learn from experience in life, but a few like recognizing mind games people play, or signs of being abused can be taught to us by others. Unless your asking for specific ques like a social worker looking for signs of a person being abused or being an abuser, in general ques can be anything. One que I see when I'm talking to nonbelievers is a causal manner of disrespect to Christians or to faith in general. They may or may not know I'm Christian, but that que speaks loud and clear that they are not Christian. Or are you asking about something besides ques to recognize who isn't a Christian? If not please rephrase the question.
To my knowledge I haven't convinced anyone to become a Christian. I hope I've encouraged people in their faith, and helped encourage people in their life in general, but who knows the heart of another person to know what our influence has been on them.