Based on the provided reference, a simple way to pair a silk shirt is with jeans to make it more casual.
Easy Pairing: Silk Shirt and Jeans
Pairing a silk shirt, which is often seen as a dressier piece, with jeans is an easy method to make the outfit more casual. The reference specifically highlights that it is "so easy to do when you pair it with a pair of jeans like these from frame."
This combination allows you to blend a luxurious fabric like silk with the everyday appeal of denim, creating a balanced look suitable for more relaxed settings.