I just dehydrate some jalapenos or spicy chiles and grind them down very small. I smoke my salt for about 20+ hours then just mix it together. If I use a coarser grind salt I will grind the chiles and salt together.
I have some stainless wire mesh screens I use to smoke the salt on and I have a sticker burner smoker. Pecan wood this time out and I soaked the wood in water so the salt would take more smoky flavor.
First pic is the finished jalapeno salt, second pic is the kosher flake I used this time to make it, third pic is the course Cyprus flake salt I also use on occasion. Later this summer I will make some spicier salt with Mosco chiles and ghost chiles.