Each icon in your design should have a distinct role to ensure a smooth user experience. Keep it straightforward: one icon for one action. Mixing and matching icons for the same purpose can disorient users and muddle your interface. Let's say you've chosen a shopping cart icon to signify "add to cart" in your design. Stick with it throughout, rather than switching to a shopping bag icon elsewhere. Consistency is key in helping users intuitively navigate your design.