"A picture speaks a thousand words". I'm sure you have heard those apt, wise, and very true words. If you can illustrate the point you are trying to make it goes a long way to helping your audience understand, grasp, and remember your talk.
Simple illustrations drawn from common things are usually best. As an example, if the thing you presenting is of such value you might compare it to gems, gold, diamonds. eg. 'this book is worth more than all the treasures of Solomon'.
Enthusiasm is like giggling, it's contagious. (I could have said enthusiasm is like the flu, it's contagious, but I think this carries a negative connotation). The point is though that your speaking with enthusiasm will excite the interest of your audience. Be careful though, if your talk is a long one, and your level of enthusiasm is too high all the way through, your audience can feel tired out, as though they have just run a marathon. So allow for a more moderate pace and a milder enthusiasm where appropriate. That way your talk will have some modulation, some majestic peaks, and pleasant strolling valleys.
Warmth is also important. Not every talk should be approached with enthusiasm, could you imagine being enthusiastic about sad but necessary news? On such occasions warmth might be more appropriate. A speaker who can convey a warm tone, a fatherly or motherly compassion, and genuine concern can do much to win over his audience.
Naturalness makes listening a pleasure. When a speaker is so tied to his notes that he reads them, or is so nervous that he has to have all his phrases word perfect, it is tiring to listen to (an uninspired boring speech), and your audience will probably take nothing away with them to benefit from.
Naturalness can be achieved by using everyday expressions, and using a conversational style rather than a written one. It is also important to try to put your audience at ease, a smile, a lighthearted comment, and natural gesturing with the hands and expressions of the face can go a long way here. Remember too that naturally you will pause at appropriate points in you sentences, so don't rush through everything, and don't make your speech like a one paced monotone reading. Be natural.
Why would you even bother with questions? Because a question deserves and often demands an answer inside in mind of your listener. What can a question do? It can arouse interest in a subject, and prepare your listener for what to expect. But think, could you also use questions to lead your listener to a correct conclusion? Absolutely, leading questions can help your listeners to reason on a subject and to come to a correct solution themselves! When you have mastered this you have taken a huge step in becoming an effective teacher, and your audience will delight in listening and learning from you, well done!
If you want your audience to listen in in first place, an interest arousing Introduction is a must. Help your listeners to see that the information is valuable and important to them, if you do, you have captured their attention, and they are more likely to listen to your subject.
Now in conclusion... How will you end your talk? Can you include a short summary of the main points to help your audience to remember. Also short motivating sentences, encouraging your listeners to act on what they have heard and that you have helped them to understand.
Example - "Friends, can you see how an interest arousing introduction, a motivating conclusion, the use of illustrations and questions, being natural, yet speaking with appropriate enthusiasm and warmth will greatly enhance your public speaking. By all means then, continue to develop personally in these areas, and your public speaking will be not only a delight for you, but a pleasure and great benefit to your audience!"