Had when i worked in a preschool and kids love them! I would use colored sand instead of white salt. DIY salt tray with alphabet cards. Easy to make and kids have fun smoothing out the salt after correctly making the letter
craft sticks and velcro, these can be arranged to make shapes and letters (great busy bag idea!) L and I had a blast painting stitcks today and I bought sticky velcro circles at Michael's. We'll see if they are a hit on our next trip!