Most speeches of tribute follow this general format:

Introduction: First, acknowledge the audience (greet) and acknowledge the occasion (orient them to the tribute).  Then, introduce or reference yourself in relation to the occasion (tell the audience who you are and, if necessary or desirable, why you will be speaking). Present the topic of tribute, if it hasnt been done so by this point.
Body: Describe or explain your topic in a way that evokes emotion. Give the reasons that you feel the recipient of your tribute is a worthy choice.
Conclusion: Summarize and then end on a strong note meaningful to the audience, occasion, or topic of tribute.