Here is an example of how that can be done. My children were playing "masak-masak" (pretend cooking). My daughter decided to makeshift a mini food shop with blocks. They took turns becoming the cook, waiter and customers. Where does literacy come in? Well, a menu was written. Orders were also written down. In the end, receipts were issued. They could have made a signage for their shop's name but they didn't feel like it.
My receipt. Just realized I've been wrongly billed. Wrong total. Hehehe.
My little waitress.
The shop. Chef is hard at work.
So, the next time your kids play, play along with them and show them how their playing can be further enriched with literacy.