I have been a Toastmaster for more than 10 years and have done over a hundred speeches during that time - speaking both informally at clubs all the way to competing at speech contests. Additionally, I have evaluated more than a few hundred speeches during that time and I have seen a number of things that I have seen speakers do that I think needs to be stopped in order to become a better speaker and to have more effective speeches:
Using crutch words
Ah's, ums, er's and other crutch words are not necessarily bad but crutch words may signal to the audience that the speaker did not prepare or practice sufficiently. The next time you are speaking, notice how many crutch words you use. I am sure that you don't normally notice these things in every day conversations but during a speech or a presentation, they are very noticeable.
Ignoring the audience's cues
While you are speaking, watch the audience's faces and try to read their moods. Are they happy or excited? Are they leaning in to listen to what you are saying? Are their arms crossed? Do they have confused looks on their faces? Nobody is going to yell out from the audience that they do not understand what you are saying unless you ask them so it's up to you as a speaker to read the audience and to respond to their cues.
Grabbing the lectern or holding speaking notes
I have noticed many speakers grabbing the lectern as they are speaking. They grip it so hard that it looks like they may break it apart at any second. It's a sign of nerves. Similarly, I have also seen some speakers bringing speaking notes or flash cards up with them as they speak. While it's not necessarily a bad thing, I just think that it says something to the audience if you did not take the time to memorize your speech. Avoid grabbing the lectern and memorize your speech.
Not making eye contact with the audience
Some speakers do not look at the audience at all. When you're having a conversation with someone and they do not look into your eyes at all, what do you think about that person? They're shifty. They're hiding something. Maybe they are suspicious in some way. Some speakers have heard that eye contact is good and try to look at everybody as they speak, but their eye contact only lands on audience members for a few seconds or less.
How long should you be making eye contact with an audience member? For the length of a sentence, phrase or quote.
Stay still in the centre of the room
I have seen some speakers stand absolutely still in the centre of the room and rather than using the length or width of the room and engaging with the audience. Walk up to the audience members. Look them directly in the eyes. Speak to them as if you are speaking one on one.
Be a robot
Hands in your pockets? Arms crossed in front of you? Do what's natural and use your hands, legs, gestures and face to convey different emotions and to emphasize different points of your speech. Yes, you could just deliver a speech by standing still and not moving anything except your lips but you could also use your body language to deliver an incredibly engaging and entertaining speech.
Don't tell stories
Think about the last factoid that someone passed along to you. Now think about the last story that you read. Which one is easier to remember? I'm willing to bet that the story was easier to remember, but why? It's because as humans, we have communicated through stories over numerous generations. Have a point you want to get across to the audience? Use stories.
Be serious
I'm not saying that you can't deliver a great speech without any humour but people like to laugh! And when you laugh, you tend to remember things much better so it's not just an entertainment device but it can also be used as a memory device. Have you ever heard that speeches should be like skirts? They need to be short enough to keep it interesting but long enough to cover the essentials.
Interested in more tips on public speaking? Want to know how to create a speech in a week? Evaluate speeches critically? Check out some of my public speaking books on Amazon that I wrote based on my 10+ years of experience as a Toastmaster.