Retell a story that your child knows well, for example Little Red Riding Hood. Once they are familiar with the story decide on some bits that would be better with sound effects, for instance the sound of the axe chopping wood to introduce the woodcutter. Find household objects or your voices for each sound effect and practise telling the story with these effects added in. To finish either perform the story for someone or record the story with the sound effects for you to enjoy later.
Below is a link to a website which explains the game better than I can! You may need to do one to show your child the finished product but once they get going it is quite easy. This activity gives you loads of things to talk about promoting lots of language while taking turns for drawing. It also gives a lot of laughs as the drawings are weird and wonderful!