I came up with this game for a group I have at my school working on s-blends. They are Kindergarten age and I loved incorporating print awareness, letter knowledge, and phonemic awareness in the activity. I made strips and attached magnets to use on a magnet board. You can laminate the strips so the kids can use dry erase markers to write in the missing letter. For example, put a strip on the magnet board and point to the picture. Ask the child "What is this a picture of?" If they say it incorrectly, explain there is a sound missing. Talk about the sound missing, what sound it makes, and how two sound go together to make the word. Let the kids write in the missing letter and try again!
You don't need a magnet board, you could use it however works best for you!