Explain the sounds of the vowels. Children need to know the basic sound of the letters before they can distinguish between a long and a short sound.
Ask the children to read aloud. If a child can't read yet, encourage her to converse. Have her read (or speak) words like "fat" and "fate" in quick succession to demonstrate the different sounds of the same vowels have. Regular repetitions of such exercises can greatly help in the learning of vowel sounds.
Introduce flash cards. Visual aids such as flash cards are effective phonic tools. Combine pictures of objects with their names written next to them. Hold two cards like "man" and "mane" simultaneously. Make the cards colorful and attractive for the children to enjoy the lesson even more.
Encourage the children to read more. Reading is a great way of self-education. Ask the children to find words with long and short vowel sounds within the reading material. Make worksheets corresponding to the reading material where they can fill in the words they found.
Use the "magic e" tool. Explain to the children how the addition of the letter E to the end of a word can change the vowel sound. Elaborate with examples such as "bat and bate", "dot and dote", and so on. Ask them to think of words on their own where the magic e can be placed.