Armed with the proper patter, you want to speak it properly. Speak clearly and loudly. Enunciate distinctly. Pitch your voice so that, you can be easily heard by the spectator furthest from you. Elocution lessons never did anyone any harm, and most of us would be benefited by taking a few.
Avoid mumbling. Nothing sounds worse. Do not recite your patter mechanically like a schoolboy. It has been said that the human mind can only think of one thing at a time. The Magician, it seems, has two things to think of all the time. One is the movement and manipulation of his hands performing the desired effect, and the other is his patter. Too many performers recite their patter mechanically and put all thought and effort into what they are doing with their hands. I believe that they should do the reverse. If the human mind can think of but one thing at a time, the patter should be thought of. You should have the movement of your hands so perfected that they should almost be mechanical, thus leaving your mind free to think about the patter.
Make yourself heard. Speak just as loudly as you can without shouting. Make it easy for a person to understand what you say. They will then enjoy it the more. People do not enjoy having to strain themselves in order to hear what you have to say.
Do not speak too rapidly. It is better perhaps to speak too slowly than too rapidly. Slow speaking makes a deeper impression. Your words will be remembered longer if you speak slowly. The secret of clearness is the use of the mouth and lips. Do not be afraid to open your mouth when you talk. Put your lips to work. You are not a ventriloquist. Articulate each word, each syllable distinctly and it will be a pleasure to listen to you. Don't talk over the heads of your audience.
Talk to them and not at them. There is a distinction! Don't stare blankly at your audience while performing. Scan the faces of the audience, glancing from one to another until you have observed everyone before you. Avoid beginning your patter with a high pitch and then lowering it gradually so that the last words become indistinct. Practice constantly aloud and you will soon develop a voice that is pleasing to listen to.