Normally I would add ice to a glass, then a piece of lime, pour (in my case) gin over the ice, then top up with tonic. However, a friend of mind chills their gin in the fridge, but also pours their drink in exactly the same manner. So, my question is: If I pre-chill my gin in the fridge does it have any effect on it (other than having a much colder drink)?
Depending on how cold your gin would be served at, it aromas may be altered.
As a spirit gets warmer, it releases more volatiles, compounds that easily vaporize. We know that if a spirit is too hot, the smell of pure alcohol can be overwhelming. However, when a spirit is too cold, the aromas and tastes might seem downright non-existent. This applies to whiskeys and gins especially.
Cold gins may be okay for some, but I prefer to be able to truly taste my gins. That is why I would only add ice to it, if I had to. Even at that, I truly doubt anyone in my family would chill their gin or put ice in it.
But then, to each his own!