traceShowId is really useful because you can plug it in anywhere you want without restructuring your code, however, sometimes it outputs too much, or things you use it on do not have Show instance.
So I propose to add a simple traces function:

traces :: Show b => (a -> b) -> a -> a
traces f v = traceShow (f v) v

> fst $ traces fst (5, id)
> 5
> 5

Though it may clash with traces function defined in comonad package. However Control.Comonad.Traced also has trace, so one would need to be careful with this module anyway.