Carefully choose your story. Does the story have a strong point, idea or theme? Do the characters appeal to the age group? Is the vocabulary appropriate for your age level? Is the length suited to the age? (Rule of thumb: Attention span is about one minute more than the age.) Does it hold your interest? If so, it will probably hold the pupils attention!
Practice profusely. Read the story over and over so it becomes second nature to you. Picture the story and scenes in your mind. Think about the characters and their respective traits. Make the characters of the story come alive through your voice and expressing emotion. Vary the inflections of your voice to give meaning. Practice projecting your voice. Everyone should be able to easily hear. Tell the story aloud to yourself over and over IN FRONT OF A MIRROR! Make eye contact with yourself! Do not concentrate on memorizing word for word -- although you should always know your first and last lines by heart for a comfortable start and finish.
Be creative and have fun! Don't tell your stories in the same, old way every time. Use your imagination. Have fun with your presentation. Be creative. Whenever possible, allow the children to become involved. Don't be afraid to use puppets.
Let your nervousness be a plus. Breath deeply before starting. A certain amount of tension will help make your story telling come alive.
Have everyone's attention before starting. Wait quietly. Never raise your voice to speak above the noise.
Look directly at the children, including all members of the group. Don't look over the heads or out the window! Take in the whole group.
Hold your Bible when telling a Bible story. Helps the children associate the story to scripture. (You can Tuck your notes inside!)