Giving a birthday speech includes planning for the correct degree of formality, developing a theme appropriate to the audience, incorporating historical events that also happened on that day, and making sure that gratitude and attention are directed at the person celebrating the birthday. Giving the speech typically means striking a balance between amusing anecdotes about the celebrated individual and honoring that person.
Striking the right level of formality is an important part of giving a birthday speech. If the birthday is in a formal setting, the birthday speech is likely to be more formal than if the setting is a casual gathering of friends.
Focus the speech around a specific theme tailored to the audience. Examples of this might include focusing on the work and life achievements of the individual. Similarly, the speech can incorporate famous events that also coincide with the individual's birthday, which can be used for either serious or humorous effect.
Finally, the speech needs to focus positive attention toward the celebrated individual, even if the humor involves embarrassing this person by using a light, roasting tone. Accentuate this positive attention by thanking the audience for the opportunity to give the speech and by ending in a toast to the person celebrating a birthday.