Regardless of religion, what do you do if someone hands out a tract and speaks to you about their faith?

I will give them a chance to say what they have to and being knowledgeable of all Christian denominations I know their heresies. The same with non Christian belief systems, I do not debate or have dialog with them unless I am familiar with the tenants of their faith. If one is Christian it helps to be grounded in the Word that way you are aware of the truth and can't be tossed to and fro by every wind and doctrine claiming truth.