Appealing to logic may be the hardest of the three sources of influence for the speaker to use. Three types of support material commonly used include examples, statistics, and testimony. Examples are useful in clarifying, reinforcing, or personalizing ideas. Ethically, you should help your audience gauge the credibility of your sources, the representativeness of examples and samples, etc. Using examples without other types of support material can come across as weak evidence.
Statistics can help.
Combing them with examples can be powerful. Using too many statistics can be deadly. You should qualify the sample, translate the statistics that you use so the audience can understand fairly. Relevant visual display of statistics can be a powerful aid in making an argument. Personal testimony can also provide dramatic support material.