Learn to control your breath by practicing holding and exhaling through your nose in a controlled manner. Slow controlled breathing is essential to learning ventriloquism.
Learn the sky technique. This technique involves placing your tongue flat on the roof of your mouth and pushing sound up. Make a bee sound using this technique. Practice until you can produce a sound that appears to be coming from some distance away. Practice this technique daily.
Attempt to curl your tongue against your teeth and produce the same sounds as in the previous step. This is called the level technique and should also be practiced daily.
Push your chin forward and once again repeat the same sound. This is called the ground technique.
Once all three techniques are mastered, practice moving from one to the next repeatedly.