Speak slowly and clearly, so your child has a chance to hear the sounds in your words.
When your child's sentences are unclear, repeat what you have understood in a slow, clear manner to confirm what has been said, and to provide a good speech model.
Exaggerate sounds in your speech that your child doesn't say correctly and be repetitious, e.g., "You want your juice? Okay, here is your juice. Don't spill your juice."
Don't interrupt your child to correct sounds. Often what he has to say is more important than how he is saying it.
If your child is not using a sound correctly in his speech, practice making the sound by itself. Play sound imitation games - using a mirror might help. Again, lengthen and emphasize the sound, and have your child watch and listen.
Read stories to your child. This is a good listening activity. When your child is familiar with a story, have him/her fill in parts of it too.
If you want to encourage specific sounds that your child doesn't have, make sure it is an appropriate sound for his age. Don't expect too much, too soon! This can be frustration for yourself and your child!
When practicing speech with your child, be enthusiastic and make it fun. Don't try to force him to listen and imitate - choose times when he is attentive and interested in what you're doing.
Practice saying nursery rhymes, poems, or songs with your child - make them slow and rhythmic, with emphasis on sounds and words.
Keep a scrap book with pictures containing the sounds you'd like your child to learn. Let him cut out the pictures and paste them in a book.
Praise and reward your child for all of his attempts and successes. This can be in the form of hugs, kisses, smiles, cheers, etc., or small token rewards such as stickers or allowing a favourite activity.
Pair specific sounds with an action or object to make them more fun and interesting, e.g., "I'm drawing a red circle, a blue circle, and a yellow circle."
Kid Talk Video: