Writing a speech in general can be a challenging endeavor; however, when you write about family members, the task becomes even more daunting. The trick to a successful speech about a family member is to balance between facts and sticking with a theme plus adding anecdotal information that gives the speech a personal touch. A speech about your son could serve any number of purposes, from talking about the hardships of raising a male child and the pitfalls to anticipate, to discussing specific situations in which your son has overcome a common youth issue.
Determine a theme so your speech remains focused. This is key because despite the fact that your speech is about your child, there still needs to be an underlying point to keep your audience interested in what you have to say. Generally, a speech about your child will center on some component of child rearing or some youth-related issues your son has had to overcome, which you can share with your audience. Choose the direction for your speech and stick with it throughout.
Inject humor into your speech. Speeches about children are often most successful when interspersed with humorous stories and tidbits about the focal point of your conversation with the audience. For example, you might talk about your son's struggle with bullying--which is a more serious topic--but to lighten the mood, perhaps you might interject a funny story about him bullying you in the womb with his penchant for kicking anytime you ate your favorite food. This keeps with the theme of the speech, but lightens a heavier topic.
Ask for your son's input during the writing process. Since it is about him, your son might offer constructive suggestions on elements to include, details that are a bit too personal and general feedback from the viewpoint of the audience.
Audition your speech for the rest of the family. As a group that knows your son and the story behind your speech, family members can also provide feedback on missing details, key aspects of your theme and opinions from a different viewpoint. Doing this for your family before you give your speech gives you an opportunity to go back and tweak anything you need to.