Soak dried chiles in hot water 10–15 minutes, then blend into a paste or sauce base; for jarred substitutions (chipotle), blend with a splash of soaking liquid.
Start with the listed ratio for cascabel-style flavor, then taste—if you need more nutty toast, roast the dried substitute briefly in a dry pan before blending.
If the substitute is tangier (often guajillo), reduce added vinegar/tomato brightness; if it’s smokier (chipotle), add a bit more water/stock to soften.
Adjust seasoning at the end: add salt for roundness and a tiny pinch of acid only if the swap tastes flat.