Well, I haven't had a chance to encounter trolls in FH yet seeing as I can't enter the game due to my username being too long...(and I haven't caught registration again for a new acc) however, I do have troll experiences in general.
If someone trolls me, I just troll them back, 10x harder until they run away. I get creepy.
The best way to deal with trolls is to creep them out until they run.~
Or just say the most random things whenever they message you.
Example:
Troll: *insert trolling comment here*
Me: I have dead people in my closet.
Troll: O.o *more trolling*
Me: My favorite color is ham.
Troll: ...? -Trolls-
Me: I hate trees.
Troll: -Leaves.-