Here’s a video with some great ideas for using flash cards in the classroom. Its presented by Carol Read, a leading author of teaching English to Young Learners.
I’ve noticed a lot of teachers at my school use PowerPoint for introducing new language. I like to use a combination of realia (always preferred), flash cards, and sometimes PowerPoint. Flash cards are so versatile. There are so many ways you can use them that children will enjoy. Large flash cards are perfect for whole group games or activities and then you can play the same game or activity with mini-flash cards.