In general, it is best to smile and wish them a good day. Of course, your attitude is as important as your literature. If your pamphlet says vegetarianism expresses the love, compassion, and peace of Christ, but you communicate anger and hostility, the Christian vegetarian message is lost. Offer those who express greater interest something to do. For example, they may sign a petition for legislation to improve the welfare of animals on farms or they may submit their name for the mailing list of a local vegetarian advocacy group.
Food attracts people, so it s helpful to offer something without animal products.
Leafleting Handing out literature at public gatherings can be an efficient way to spread the message. I would caution against handing out CVA literature to general audiences, unless there is good reason to believe that they are predominantly Christians. Good places to hand out literature include college campuses, because students are generally open to new ideas, walkathons, which tend to attract relatively compassionate people, and street fairs. Often, a discussion can be rewarding for both you and the audience. It is sometimes helpful to reflect on two or three biblical passages as springboards for conversations.