Let's hear your ingredient substitutions

I rarely cook, but I'm a decent baker. My favorite substitution is to use cornflakes (any brand will do) to create my crumble/breading. I like the texture better and it doesn't become a soggy mess as quickly. I often reach for the cornflakes even when I have the traditional ingredients or kits in my pantry. What are some of your favorite substitutions?

I usually follow the recipe, but it's nice to know what I can use in a pinch when I've already started and realize I'm missing a key ingredient. I've used crackers for my breading in a pinch before.