Loosen up your tongue by doing some tongue twisters, which also limber up your mind. Tongue twisters help you to enunciate vowels and consonants correctly and make your voice more articulate. Start off slowly at first, pronouncing each word clearly, then gradually go as fast as you can without stumbling over words.
Do some body movements while you are doing your tongue twisters to keep from looking stiff during your speech. Try stomping your feet, bouncing, moving from side to side or even skipping to the beat of your tongue twister.
Try chewing some virtual bubble gum to work the muscles in your face and tongue to loosen them up and prepare you to speak. Stick an imaginary piece of gum in your mouth, then another and another. Feel the tingle in your lips as you work those muscles.
Keep yourself from pushing your words into the back of your mouth, which can give you a nasal sound, by doing tongue stretches. Open your mouth just slightly and place the tip of your tongue inside the top of your lower teeth. Push your tongue against your teeth and feel the stretch.
Hold on to something, such as a chair, and stand on one foot while shaking the other leg. Switch legs and do the same thing on the alternate side. Imagine the energy going up from your legs and out through your head.
Shake your hands out, then hold them above your head and bring them back down. Twist your hands at the wrist as if you are conducting an orchestra. With this exercise, you are loosening up your hands to make any hand appear more natural.
Roll your shoulders frontward and backward. Do some neck rolls, and now you are prepared and ready to go.