frost arrows are great; you will use them to slow trolls and berserkers and I think
they work really well against sea serpents BUT they're more involved to make than
fire arrows and require a level 4 workbench

nothing really wants to be set on fire; it illuminates them so they're easier to see
in the dark, root monsters are weak to fire and you can make them on a level 2
workbench

I think the arrow that you will eventually want to always have are needle arrows