Sticky glazes, like honey garlic or teriyaki, are tough on cast iron.
The sugar in these sauces can burn and cling to the surface, making a mess and harming your pan’s seasoning. Cleanup becomes a nightmare, and your skillet might lose some of its nonstick quality.
4. Eggs — Unless You’re a Pro

Yes, some people can make eggs in cast iron. But unless your pan is perfectly seasoned, eggs are likely to stick.
Scraping them off can scratch the surface and leave behind a residue that’s tough to clean.
If you’re still building up the seasoning on your skillet, skip the eggs for now.
Try instead: Use a nonstick skillet for scrambled or sunny-side-up eggs. Once your cast iron is well seasoned, you can experiment.
5. Strongly Flavored Foods (Like Garlic and Curry)
Cast iron absorbs flavors and odors — especially if it hasn’t been seasoned over years of use.
If you cook a garlicky stir-fry or a spicy curry, don’t be surprised if your next dish has a little “extra flavor” from the last one.
And while that might not be a problem for savory meals, it’s a big issue if you want to bake something sweet in the same pan.
What to do: Either deep-clean your skillet after strong meals or keep one pan for sweets and another for savory cooking.