The Hobbit - Chapter 10 - A Warm Welcome

[Tuor of Gondolin]

No "shoot on sight" policy, eh?

Well, perhaps not, but I think that the treatment the Dwarves suffered at the hands of Thranduil and his men ought to be a pretty clear demonstration of the exact nature of the Mirkwood Elves- good to their friends, such as the Lakemen, but woe betide any unknown travellers...

Treatment of the dwarves could be considered a special case,
especially since Thranduil was a Sindar, and had, no doubt,
heard tales of the dwarves behavior against elves in the First Age.
It's interesting that Tolkien has two positive (exceptional?)
cases of peoples interaction/organization in the Hobbit not (I
believe) seen as such in other works, specifically the governmental
structure in Laketown and the view of races by the Laketown polity.
And weren't the Laketowners (Laketownites ) Edain related
who either didn't go into Beleriand or came back while not going to
Numenor?