First of all, here are a few of the reasons I've heard for why someone would want to be better at public speaking:
1. To open up more opportunities at work by taking on greater responsibilities
2. To build reputation and visibility in their field
3. To stop dreading requests to speak by dealing with speaking anxiety
3. To have a unique voice and be heard, both at work and in personal life
4. To be more effective at expressing themselves
5. To build confidence, self-esteem and self-respect
6. To have a marketable skill when changing jobs or starting a business
There are a lot of reasons that a person would want to improve their speaking skills, which mostly tend to boil down to:
But you'll never reach these goals or reap the benefits without practice.
One of the most difficult habits to change for part-time or unpaid speakers (those of you who speak occasionally as part of your job or for community events) is the habit of not practicing, or waiting until the last minute to practice a presentation.
I hear the argument, "I'm so busy," more than any other argument against practicing. If this is a work presentation, you explain that you have too much other work. Yet -- somehow -- you manage to get your other work done.
If this is a presentation outside of work, you explain that you have kids to pick up, a volunteer meeting to attend and errands to run, yet -- somehow -- you manage to find time to watch your favorite TV show, meet a friend for drinks or get a manicure.
If you don't WANT to practice, that's your choice. But be honest about it. Not to me -- to yourself.
Realize that you are making choices about how you spend your time. Realize that you are choosing what you prioritize as important.
And realize that your presentation is only as good as the time you take to make it good.
When your work is (pardon the expression) half-ass, it shows. If you truly want to be a better speaker (and you say you do), and you want to take advantage of the benefits listed above, then practice is required. Time is required. And not the day before it's due, for five minutes, in your head.
If you want to be a better speaker, for any of the reasons listed above and more, figure out how to prioritize your time to make practice part of every presentation you create. Make the choice to fit it into your schedule.
It's pretty rare in this life to get something for nothing. Success comes from hard work. Hard work includes practicing your skills so you get better at whatever it is you choose -- in this case, public speaking.
No more excuses. No more arguments. Make the time. You will be rewarded.
If you need more arguments in favor of practice, check out these posts:
Practice makes... improvement (video)
Winging it -- not okay
What's your excuse for not being prepared?
Seven ways to practice public speaking at work
Doing the bare minimum
Inspired to speak: The King's Speech
Experience vs. practice
Practice like you mean it