Hello dear! My name is Annina. I feel your distress what it comes to your great assignment on your older brother's wedding day. I would like to know more about you and the wedding couple and after a little chat I feel that I am more than capable of completing this content writing job for you. I think the most important thing is to make the speech look like your own.
Some of the things I would consider when writing this speech for you:
-Humorous attitude
-How close you are with your brother, your childhood memories, funny accidents etc.
-Your religion
-Formal or permissive audience/wedding
-Your family connections
-Your brother's interests and hobbies, his character
Thank you, hope to hear from you. Annina