You need to make sure to do regular safety inspections in your evil lair. It might be funny when one of your minions get flattened by a steel beam, but the Famous Hero dying accidentally, not because they were a fool, or because you outsmarted them, but because you were neglectful, would just not be very satisfying would it?

I covered my evil lair with talcum powder so that spider-man sticks to that instead of my walls. But I don't have any powers or weapons so he just beat my ass normal style. Didn't even joke about the talcum powder. I'd like to think it confused him too much. It's the little victories I suppose.