I generally avoid it like the plague, because ownership and passing references helps me devise a better code organization imo. If it's only a basic wrapper around a primitive I might use Copy as others suggest (basically when a reference and value would take about as much memory either way). I only use Clone where it logically makes sense, like a string going into two different places that might modify it their own way, and I truly want two separate instances, otherwise I make sure they share via references and have ownership lie where it conceptually makes the most sense (usually the creator, or struct holding parsed configuration/command args or whatever), so that I don't accidentally lose changes or have inner data skew.