It's quicker and simpler to write a keynote speech -- or any speech -- that you're delivering.
There's no client or boss who needs to give the OK; it's just you and the blank screen to fill.
But it's also dangerous to write for yourself.
Everybody Needs An Editor
You'll be tempted to write it much later, to give yourself a lot less time to draft and practice the speech. The first draft is fine, right? I don't need to practice. I'll just wing it. No.
You'll be tempted to say all the brilliant, hilarious things that your boss or client would never, ever say. What you may think is edgy and hilarious and amazing may come across to an audience as weird, bizarre or completely unfunny.
If your writing for yourself, pick at least two editors. Not spouses or neighbors or best friends. Call up people who work with words for a living and bribe them to take a look.
Have a different set of people listen to you practice the speech.
If you keep getting the same comments, change the speech.
Film Room
Tape yourself practicing the speech. Use a smart phone or a cheap video camera -- it doesn't have to be high-definition video. Try to replicate the venue as much as you can: walk in with your notes, put them down on a table or lectern and pretend there's an audience.
1) Watch the video the first time with the sound off.
Have somebody you trust watch it with you. Do you walk in nervously, with your head down? Do you fumble with the notes in the first five seconds before starting?
You should know at least the first two lines of the speech by heart, so you don't need to look down at your notes. It's more important to connect with audience right away than to read every word perfectly.
2) Close your eyes and play the video with the sound on.
Don't worry about verbal fumbles. Worry about the tone and pacing of your voice.
Do you read every line the same, with the same emotion and speed? Does your voice speed up and slow down at times? Do you ever pause during a moment of high emotion?
The biggest mistake rookie speakers make is to gallop through their speech like it's a footrace. It's a roller-coaster ride. Mark the parts of the speech where you should slow down, or speed up, or inject more emotion.