Think back to the last time you heard someone give a speech by reading words directly off a card. How bored were you? If you want to avoid having the same effect on your own audience, practice your speech by having a conversation with someone about it.
Photo by re:publica.
As advice site Mental Floss suggests, audiences respond well to speeches given in a conversational tone. When you're practicing, ask a friend to sit with you and talk about the topic. You can present the same information, but allow your friend to ask questions, or give you feedback. Not only can this help you improve your presentation, but you can get a feel for how to talk about it without a huge audience:
As tempting as it may be to type up a speech and read it word for word, refrain from doing so. Audiences listen better when the speaker talks to them instead of reads to them... In other words, if you change your natural speech patterns to give a speech that's written like an essay you're setting yourself up to fail.
When you're giving the speech to an audience, they probably won't be asking questions directly. Knowing what questions your friend asked, however, can give you insight into how they're thinking. More importantly, if you're delivering your speech as though you were explaining it to a friend, your audience is more likely to respond in a friendly way.
5 Steps to Becoming a Better Public Speaker [Mental Floss]